diff --git a/src/main/java/com/ethlo/time/DateTime.java b/src/main/java/com/ethlo/time/DateTime.java
index c62c03c..c28431f 100644
--- a/src/main/java/com/ethlo/time/DateTime.java
+++ b/src/main/java/com/ethlo/time/DateTime.java
@@ -20,11 +20,11 @@
  * #L%
  */
 
-import static com.ethlo.time.internal.ITUParser.DATE_SEPARATOR;
-import static com.ethlo.time.internal.ITUParser.SEPARATOR_UPPER;
-import static com.ethlo.time.internal.ITUParser.TIME_SEPARATOR;
-import static com.ethlo.time.internal.ITUFormatter.finish;
-import static com.ethlo.time.internal.LeapSecondHandler.LEAP_SECOND_SECONDS;
+import static com.ethlo.time.internal.fixed.ITUFormatter.finish;
+import static com.ethlo.time.internal.fixed.ITUParser.DATE_SEPARATOR;
+import static com.ethlo.time.internal.fixed.ITUParser.SEPARATOR_UPPER;
+import static com.ethlo.time.internal.fixed.ITUParser.TIME_SEPARATOR;
+import static com.ethlo.time.internal.util.LeapSecondHandler.LEAP_SECOND_SECONDS;
 
 import java.time.DateTimeException;
 import java.time.Instant;
@@ -43,10 +43,10 @@
 import java.util.Optional;
 
 import com.ethlo.time.internal.DateTimeFormatException;
-import com.ethlo.time.internal.DateTimeMath;
-import com.ethlo.time.internal.DefaultLeapSecondHandler;
-import com.ethlo.time.internal.LeapSecondHandler;
-import com.ethlo.time.internal.LimitedCharArrayIntegerUtil;
+import com.ethlo.time.internal.util.DateTimeMath;
+import com.ethlo.time.internal.util.DefaultLeapSecondHandler;
+import com.ethlo.time.internal.util.LeapSecondHandler;
+import com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil;
 
 /**
  * Container class for parsed date/date-time data. The {@link #getMostGranularField()} contains the highest granularity field found, like MONTH, MINUTE, SECOND.
diff --git a/src/main/java/com/ethlo/time/Field.java b/src/main/java/com/ethlo/time/Field.java
index d131c5b..3ef84c1 100644
--- a/src/main/java/com/ethlo/time/Field.java
+++ b/src/main/java/com/ethlo/time/Field.java
@@ -40,7 +40,8 @@ public enum Field
     HOUR(13),
     MINUTE(16),
     SECOND(19),
-    NANO(20);
+    NANO(20),
+    ZONE_OFFSET(17);
 
     private final int requiredLength;
 
diff --git a/src/main/java/com/ethlo/time/ITU.java b/src/main/java/com/ethlo/time/ITU.java
index 633e8c0..4d51227 100644
--- a/src/main/java/com/ethlo/time/ITU.java
+++ b/src/main/java/com/ethlo/time/ITU.java
@@ -29,8 +29,8 @@
 import java.time.YearMonth;
 import java.time.format.DateTimeParseException;
 
-import com.ethlo.time.internal.ITUFormatter;
-import com.ethlo.time.internal.ITUParser;
+import com.ethlo.time.internal.fixed.ITUFormatter;
+import com.ethlo.time.internal.fixed.ITUParser;
 
 /**
  * The main access to the parse and formatting functions in this library.
@@ -71,7 +71,8 @@ public static DateTime parseLenient(String text)
 
     /**
      * Allows parsing leniently with {@link ParseConfig to control some aspects of the parsing}
-     * @param text The text to parse
+     *
+     * @param text        The text to parse
      * @param parseConfig The configuration to use for parsing
      * @return The date-time parsed
      */
@@ -81,10 +82,9 @@ public static DateTime parseLenient(String text, ParseConfig parseConfig)
     }
 
     /**
-     *
-     * @param text The text to parse
+     * @param text        The text to parse
      * @param parseConfig The configuration to use for parsing
-     * @param position The position to start parsing from. The index (and the errorIndex, if an error occurs) is updated after the parsing process has completed
+     * @param position    The position to start parsing from. The index (and the errorIndex, if an error occurs) is updated after the parsing process has completed
      * @return The date-time parsed
      */
     public static DateTime parseLenient(String text, ParseConfig parseConfig, ParsePosition position)
diff --git a/src/main/java/com/ethlo/time/ParseConfig.java b/src/main/java/com/ethlo/time/ParseConfig.java
index ae61a22..a038ee2 100644
--- a/src/main/java/com/ethlo/time/ParseConfig.java
+++ b/src/main/java/com/ethlo/time/ParseConfig.java
@@ -20,13 +20,11 @@
  * #L%
  */
 
-import static com.ethlo.time.internal.ITUParser.SEPARATOR_LOWER;
-import static com.ethlo.time.internal.ITUParser.SEPARATOR_SPACE;
-import static com.ethlo.time.internal.ITUParser.SEPARATOR_UPPER;
-
 import java.util.Arrays;
 import java.util.Optional;
 
+import static com.ethlo.time.internal.fixed.ITUParser.*;
+
 public class ParseConfig
 {
     private static final char[] DEFAULT_DATE_TIME_SEPARATORS = new char[]{SEPARATOR_UPPER, SEPARATOR_LOWER, SEPARATOR_SPACE};
diff --git a/src/main/java/com/ethlo/time/TimezoneOffset.java b/src/main/java/com/ethlo/time/TimezoneOffset.java
index cdbe781..3a2a5c0 100644
--- a/src/main/java/com/ethlo/time/TimezoneOffset.java
+++ b/src/main/java/com/ethlo/time/TimezoneOffset.java
@@ -29,6 +29,9 @@
 public class TimezoneOffset
 {
     public static final TimezoneOffset UTC = new TimezoneOffset(0, 0);
+    private static final int SECONDS_PER_HOUR = 3600;
+    private static final int SECONDS_PER_MINUTE = 60;
+    private static final int MINUTES_PER_HOUR = 60;
     private final int hours;
     private final int minutes;
 
@@ -43,6 +46,13 @@ public static TimezoneOffset ofHoursMinutes(int hours, int minutes)
         return new TimezoneOffset(hours, minutes);
     }
 
+    public static TimezoneOffset ofTotalSeconds(int seconds)
+    {
+        final int absHours = seconds / SECONDS_PER_HOUR;
+        int absMinutes = (seconds / SECONDS_PER_MINUTE) % MINUTES_PER_HOUR;
+        return ofHoursMinutes(absHours, absMinutes);
+    }
+
     public static TimezoneOffset of(ZoneOffset offset)
     {
         final int seconds = offset.getTotalSeconds();
diff --git a/src/main/java/com/ethlo/time/internal/ITUFormatter.java b/src/main/java/com/ethlo/time/internal/fixed/ITUFormatter.java
similarity index 87%
rename from src/main/java/com/ethlo/time/internal/ITUFormatter.java
rename to src/main/java/com/ethlo/time/internal/fixed/ITUFormatter.java
index 56c7ad2..1efe741 100644
--- a/src/main/java/com/ethlo/time/internal/ITUFormatter.java
+++ b/src/main/java/com/ethlo/time/internal/fixed/ITUFormatter.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.fixed;
 
 /*-
  * #%L
@@ -9,9 +9,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,20 +20,22 @@
  * #L%
  */
 
-import static com.ethlo.time.internal.ITUParser.DATE_SEPARATOR;
-import static com.ethlo.time.internal.ITUParser.FRACTION_SEPARATOR;
-import static com.ethlo.time.internal.ITUParser.MAX_FRACTION_DIGITS;
-import static com.ethlo.time.internal.ITUParser.MINUS;
-import static com.ethlo.time.internal.ITUParser.PLUS;
-import static com.ethlo.time.internal.ITUParser.SEPARATOR_UPPER;
-import static com.ethlo.time.internal.ITUParser.TIME_SEPARATOR;
-import static com.ethlo.time.internal.ITUParser.ZULU_UPPER;
+import static com.ethlo.time.internal.fixed.ITUParser.DATE_SEPARATOR;
+import static com.ethlo.time.internal.fixed.ITUParser.FRACTION_SEPARATOR;
+import static com.ethlo.time.internal.fixed.ITUParser.MAX_FRACTION_DIGITS;
+import static com.ethlo.time.internal.fixed.ITUParser.MINUS;
+import static com.ethlo.time.internal.fixed.ITUParser.PLUS;
+import static com.ethlo.time.internal.fixed.ITUParser.SEPARATOR_UPPER;
+import static com.ethlo.time.internal.fixed.ITUParser.TIME_SEPARATOR;
+import static com.ethlo.time.internal.fixed.ITUParser.ZULU_UPPER;
 
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
 
 import com.ethlo.time.Field;
 import com.ethlo.time.TimezoneOffset;
+import com.ethlo.time.internal.DateTimeFormatException;
+import com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil;
 
 public class ITUFormatter
 {
diff --git a/src/main/java/com/ethlo/time/internal/ITUParser.java b/src/main/java/com/ethlo/time/internal/fixed/ITUParser.java
similarity index 91%
rename from src/main/java/com/ethlo/time/internal/ITUParser.java
rename to src/main/java/com/ethlo/time/internal/fixed/ITUParser.java
index e32b3b8..e608441 100644
--- a/src/main/java/com/ethlo/time/internal/ITUParser.java
+++ b/src/main/java/com/ethlo/time/internal/fixed/ITUParser.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.fixed;
 
 /*-
  * #%L
@@ -20,13 +20,13 @@
  * #L%
  */
 
-import static com.ethlo.time.internal.ErrorUtil.assertFractionDigits;
-import static com.ethlo.time.internal.ErrorUtil.assertPositionContains;
-import static com.ethlo.time.internal.ErrorUtil.raiseUnexpectedCharacter;
-import static com.ethlo.time.internal.ErrorUtil.raiseUnexpectedEndOfText;
-import static com.ethlo.time.internal.LimitedCharArrayIntegerUtil.DIGIT_9;
-import static com.ethlo.time.internal.LimitedCharArrayIntegerUtil.ZERO;
-import static com.ethlo.time.internal.LimitedCharArrayIntegerUtil.parsePositiveInt;
+import static com.ethlo.time.internal.util.ErrorUtil.assertFractionDigits;
+import static com.ethlo.time.internal.util.ErrorUtil.assertPositionContains;
+import static com.ethlo.time.internal.util.ErrorUtil.raiseUnexpectedCharacter;
+import static com.ethlo.time.internal.util.ErrorUtil.raiseUnexpectedEndOfText;
+import static com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil.DIGIT_9;
+import static com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil.ZERO;
+import static com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil.parsePositiveInt;
 
 import java.time.OffsetDateTime;
 import java.time.format.DateTimeParseException;
@@ -36,6 +36,7 @@
 import com.ethlo.time.Field;
 import com.ethlo.time.ParseConfig;
 import com.ethlo.time.TimezoneOffset;
+import com.ethlo.time.internal.util.ArrayUtils;
 
 public class ITUParser
 {
@@ -44,11 +45,11 @@ public class ITUParser
     public static final char SEPARATOR_UPPER = 'T';
     public static final char SEPARATOR_LOWER = 't';
     public static final char SEPARATOR_SPACE = ' ';
-    static final char PLUS = '+';
-    static final char MINUS = '-';
+    public static final char PLUS = '+';
+    public static final char MINUS = '-';
     public static final char FRACTION_SEPARATOR = '.';
-    static final char ZULU_UPPER = 'Z';
-    private static final char ZULU_LOWER = 'z';
+    public static final char ZULU_UPPER = 'Z';
+    public static final char ZULU_LOWER = 'z';
     public static final int MAX_FRACTION_DIGITS = 9;
     public static final int RADIX = 10;
     public static final int DIGITS_IN_NANO = 9;
@@ -76,7 +77,7 @@ private static DateTime handleTime(final int offset, final ParseConfig parseConf
                 return new DateTime(Field.MINUTE, year, month, day, hour, minute, 0, 0, zoneOffset, 0, charLength);
 
             default:
-                throw raiseUnexpectedCharacter(chars, offset + 16);
+                throw raiseUnexpectedCharacter(chars, offset + 16, TIME_SEPARATOR, ZULU_UPPER, ZULU_LOWER, PLUS, MINUS);
         }
     }
 
@@ -109,7 +110,7 @@ private static TimezoneOffset parseTimezone(int offset, final ParseConfig parseC
         final char sign = chars.charAt(idx);
         if (sign != PLUS && sign != MINUS)
         {
-            raiseUnexpectedCharacter(chars, idx);
+            raiseUnexpectedCharacter(chars, idx, ZULU_UPPER, ZULU_LOWER, PLUS, MINUS);
         }
 
         if (left < 6)
@@ -258,7 +259,7 @@ else if (c == PLUS || c == MINUS)
             }
             else
             {
-                throw raiseUnexpectedCharacter(chars, offset + 19);
+                throw raiseUnexpectedCharacter(chars, offset + 19, ArrayUtils.merge(parseConfig.getFractionSeparators(), new char[]{ZULU_UPPER, ZULU_LOWER, PLUS, MINUS}));
             }
         }
         else if (length == 19)
diff --git a/src/main/java/com/ethlo/time/internal/token/DigitsToken.java b/src/main/java/com/ethlo/time/internal/token/DigitsToken.java
new file mode 100644
index 0000000..1674c7f
--- /dev/null
+++ b/src/main/java/com/ethlo/time/internal/token/DigitsToken.java
@@ -0,0 +1,60 @@
+package com.ethlo.time.internal.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import java.text.ParsePosition;
+
+import com.ethlo.time.Field;
+import com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil;
+import com.ethlo.time.token.DateTimeToken;
+
+public class DigitsToken implements DateTimeToken
+{
+    private final Field field;
+    private final int length;
+
+    public DigitsToken(Field field, int length)
+    {
+        this.field = field;
+        this.length = length;
+    }
+
+    @Override
+    public int read(String text, ParsePosition parsePosition)
+    {
+        final int offset = parsePosition.getIndex();
+        final int end = offset + length;
+        final int value = LimitedCharArrayIntegerUtil.parsePositiveInt(text, offset, end);
+        parsePosition.setIndex(end);
+        return value;
+    }
+
+    public Field getField()
+    {
+        return field;
+    }
+
+    @Override
+    public String toString()
+    {
+        return "digits: " + field + "(" + length + ")";
+    }
+}
diff --git a/src/main/java/com/ethlo/time/internal/token/FractionsToken.java b/src/main/java/com/ethlo/time/internal/token/FractionsToken.java
new file mode 100644
index 0000000..9825403
--- /dev/null
+++ b/src/main/java/com/ethlo/time/internal/token/FractionsToken.java
@@ -0,0 +1,61 @@
+package com.ethlo.time.internal.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import static com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil.DIGIT_9;
+import static com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil.ZERO;
+
+import java.text.ParsePosition;
+
+import com.ethlo.time.Field;
+import com.ethlo.time.token.DateTimeToken;
+
+public class FractionsToken implements DateTimeToken
+{
+    @Override
+    public int read(final String text, final ParsePosition parsePosition)
+    {
+        int idx = parsePosition.getIndex();
+        final int length = text.length();
+        int value = 0;
+        while (idx < length)
+        {
+            final char c = text.charAt(idx);
+            if (c < ZERO || c > DIGIT_9)
+            {
+                break;
+            }
+            else
+            {
+                value = value * 10 + (c - ZERO);
+                idx++;
+            }
+        }
+        parsePosition.setIndex(idx);
+        return value;
+    }
+
+    @Override
+    public Field getField()
+    {
+        return Field.NANO;
+    }
+}
diff --git a/src/main/java/com/ethlo/time/internal/token/SeparatorToken.java b/src/main/java/com/ethlo/time/internal/token/SeparatorToken.java
new file mode 100644
index 0000000..f12ce1e
--- /dev/null
+++ b/src/main/java/com/ethlo/time/internal/token/SeparatorToken.java
@@ -0,0 +1,62 @@
+package com.ethlo.time.internal.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import java.text.ParsePosition;
+
+import com.ethlo.time.internal.util.ErrorUtil;
+import com.ethlo.time.token.DateTimeToken;
+
+public class SeparatorToken implements DateTimeToken
+{
+    private final char separator;
+
+    public SeparatorToken(char separator)
+    {
+        this.separator = separator;
+    }
+
+    @Override
+    public int read(final String text, final ParsePosition parsePosition)
+    {
+        final int index = parsePosition.getIndex();
+        if (text.length() > index && text.charAt(index) == separator)
+        {
+            parsePosition.setIndex(index + 1);
+        }
+        else if (text.length() <= index)
+        {
+            ErrorUtil.raiseUnexpectedEndOfText(text, text.length());
+        }
+        else if (text.charAt(index) != separator)
+        {
+            ErrorUtil.raiseUnexpectedCharacter(text, index, separator);
+        }
+        parsePosition.setIndex(index + 1);
+        return 1;
+    }
+
+    @Override
+    public String toString()
+    {
+        return "separator: " + separator;
+    }
+}
diff --git a/src/main/java/com/ethlo/time/internal/token/SeparatorsToken.java b/src/main/java/com/ethlo/time/internal/token/SeparatorsToken.java
new file mode 100644
index 0000000..1e6f656
--- /dev/null
+++ b/src/main/java/com/ethlo/time/internal/token/SeparatorsToken.java
@@ -0,0 +1,65 @@
+package com.ethlo.time.internal.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import java.text.ParsePosition;
+import java.time.format.DateTimeParseException;
+import java.util.Arrays;
+
+import com.ethlo.time.internal.util.ErrorUtil;
+import com.ethlo.time.token.DateTimeToken;
+
+public class SeparatorsToken implements DateTimeToken
+{
+    private final char[] separators;
+
+    public SeparatorsToken(char... separators)
+    {
+        this.separators = separators;
+    }
+
+    @Override
+    public int read(final String text, final ParsePosition parsePosition)
+    {
+        final int index = parsePosition.getIndex();
+        if (text.length() <= index)
+        {
+            ErrorUtil.raiseUnexpectedEndOfText(text, text.length());
+        }
+
+        final char c = text.charAt(index);
+        for (char sep : separators)
+        {
+            if (c == sep)
+            {
+                parsePosition.setIndex(index + 1);
+                return 1;
+            }
+        }
+        throw new DateTimeParseException(String.format("Expected character %s at position %d, found %s: %s", Arrays.toString(separators), index + 1, text.charAt(index), text), text, index);
+    }
+
+    @Override
+    public String toString()
+    {
+        return "separators: " + Arrays.toString(separators);
+    }
+}
diff --git a/src/main/java/com/ethlo/time/internal/token/ZoneOffsetToken.java b/src/main/java/com/ethlo/time/internal/token/ZoneOffsetToken.java
new file mode 100644
index 0000000..a253872
--- /dev/null
+++ b/src/main/java/com/ethlo/time/internal/token/ZoneOffsetToken.java
@@ -0,0 +1,90 @@
+package com.ethlo.time.internal.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import static com.ethlo.time.internal.fixed.ITUParser.MINUS;
+import static com.ethlo.time.internal.fixed.ITUParser.PLUS;
+import static com.ethlo.time.internal.fixed.ITUParser.ZULU_LOWER;
+import static com.ethlo.time.internal.fixed.ITUParser.ZULU_UPPER;
+import static com.ethlo.time.internal.util.ErrorUtil.raiseUnexpectedCharacter;
+import static com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil.parsePositiveInt;
+
+import java.text.ParsePosition;
+import java.time.format.DateTimeParseException;
+
+import com.ethlo.time.Field;
+import com.ethlo.time.token.DateTimeToken;
+
+public class ZoneOffsetToken implements DateTimeToken
+{
+    @Override
+    public int read(final String text, final ParsePosition parsePosition)
+    {
+        final int idx = parsePosition.getIndex();
+        final int len = text.length();
+        final int left = len - idx;
+
+        if (left < 1)
+        {
+            return -1;
+        }
+
+        final char c = text.charAt(idx);
+        if (c == 'Z' || c == 'z')
+        {
+            parsePosition.setIndex(idx + 1);
+            return 0;
+        }
+
+        final char sign = text.charAt(idx);
+        if (sign != '+' && sign != '-')
+        {
+            raiseUnexpectedCharacter(text, idx, ZULU_UPPER, ZULU_LOWER, PLUS, MINUS);
+        }
+
+        if (left < 6)
+        {
+            throw new DateTimeParseException(String.format("Invalid timezone offset: %s", text), text, idx);
+        }
+
+        int hours = parsePositiveInt(text, idx + 1, idx + 3);
+        int minutes = parsePositiveInt(text, idx + 4, idx + 4 + 2);
+        if (sign == '-')
+        {
+            hours = -hours;
+            minutes = -minutes;
+
+            if (hours == 0 && minutes == 0)
+            {
+                throw new DateTimeParseException("Unknown 'Local Offset Convention' date-time not allowed", text, idx);
+            }
+        }
+
+        parsePosition.setIndex(idx + 6);
+        return hours * 3600 + minutes * 60;
+    }
+
+    @Override
+    public Field getField()
+    {
+        return Field.ZONE_OFFSET;
+    }
+}
diff --git a/src/main/java/com/ethlo/time/internal/util/ArrayUtils.java b/src/main/java/com/ethlo/time/internal/util/ArrayUtils.java
new file mode 100644
index 0000000..e2ae22d
--- /dev/null
+++ b/src/main/java/com/ethlo/time/internal/util/ArrayUtils.java
@@ -0,0 +1,32 @@
+package com.ethlo.time.internal.util;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+public class ArrayUtils
+{
+    public static char[] merge(char[] a, char[] b)
+    {
+        final char[] result = new char[a.length + b.length];
+        System.arraycopy(a, 0, result, 0, a.length);
+        System.arraycopy(b, 0, result, a.length, b.length);
+        return result;
+    }
+}
diff --git a/src/main/java/com/ethlo/time/internal/DateTimeMath.java b/src/main/java/com/ethlo/time/internal/util/DateTimeMath.java
similarity index 98%
rename from src/main/java/com/ethlo/time/internal/DateTimeMath.java
rename to src/main/java/com/ethlo/time/internal/util/DateTimeMath.java
index 619e45f..af43cc2 100644
--- a/src/main/java/com/ethlo/time/internal/DateTimeMath.java
+++ b/src/main/java/com/ethlo/time/internal/util/DateTimeMath.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.util;
 
 /*-
  * #%L
diff --git a/src/main/java/com/ethlo/time/internal/DefaultLeapSecondHandler.java b/src/main/java/com/ethlo/time/internal/util/DefaultLeapSecondHandler.java
similarity index 98%
rename from src/main/java/com/ethlo/time/internal/DefaultLeapSecondHandler.java
rename to src/main/java/com/ethlo/time/internal/util/DefaultLeapSecondHandler.java
index 44cdbe5..746bd32 100644
--- a/src/main/java/com/ethlo/time/internal/DefaultLeapSecondHandler.java
+++ b/src/main/java/com/ethlo/time/internal/util/DefaultLeapSecondHandler.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.util;
 
 /*-
  * #%L
diff --git a/src/main/java/com/ethlo/time/internal/ErrorUtil.java b/src/main/java/com/ethlo/time/internal/util/ErrorUtil.java
similarity index 86%
rename from src/main/java/com/ethlo/time/internal/ErrorUtil.java
rename to src/main/java/com/ethlo/time/internal/util/ErrorUtil.java
index 036138b..57e4272 100644
--- a/src/main/java/com/ethlo/time/internal/ErrorUtil.java
+++ b/src/main/java/com/ethlo/time/internal/util/ErrorUtil.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.util;
 
 /*-
  * #%L
@@ -20,9 +20,10 @@
  * #L%
  */
 
-import static com.ethlo.time.internal.ITUParser.MAX_FRACTION_DIGITS;
+import static com.ethlo.time.internal.fixed.ITUParser.MAX_FRACTION_DIGITS;
 
 import java.time.format.DateTimeParseException;
+import java.util.Arrays;
 
 import com.ethlo.time.Field;
 
@@ -32,9 +33,9 @@ private ErrorUtil()
     {
     }
 
-    public static DateTimeParseException raiseUnexpectedCharacter(String chars, int index)
+    public static DateTimeParseException raiseUnexpectedCharacter(String chars, int index, char... expected)
     {
-        throw new DateTimeParseException(String.format("Unexpected character %s at position %d: %s", chars.charAt(index), index + 1, chars), chars, index);
+        throw new DateTimeParseException(String.format("Expected character %s at position %d, found %s: %s", Arrays.toString(expected), index + 1, chars.charAt(index), chars), chars, index);
     }
 
     public static DateTimeParseException raiseUnexpectedEndOfText(final String chars, final int offset)
diff --git a/src/main/java/com/ethlo/time/internal/LeapSecondHandler.java b/src/main/java/com/ethlo/time/internal/util/LeapSecondHandler.java
similarity index 95%
rename from src/main/java/com/ethlo/time/internal/LeapSecondHandler.java
rename to src/main/java/com/ethlo/time/internal/util/LeapSecondHandler.java
index 168e7af..922d380 100644
--- a/src/main/java/com/ethlo/time/internal/LeapSecondHandler.java
+++ b/src/main/java/com/ethlo/time/internal/util/LeapSecondHandler.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.util;
 
 /*-
  * #%L
diff --git a/src/main/java/com/ethlo/time/internal/LimitedCharArrayIntegerUtil.java b/src/main/java/com/ethlo/time/internal/util/LimitedCharArrayIntegerUtil.java
similarity index 96%
rename from src/main/java/com/ethlo/time/internal/LimitedCharArrayIntegerUtil.java
rename to src/main/java/com/ethlo/time/internal/util/LimitedCharArrayIntegerUtil.java
index 18cd9d2..88960a3 100644
--- a/src/main/java/com/ethlo/time/internal/LimitedCharArrayIntegerUtil.java
+++ b/src/main/java/com/ethlo/time/internal/util/LimitedCharArrayIntegerUtil.java
@@ -1,4 +1,4 @@
-package com.ethlo.time.internal;
+package com.ethlo.time.internal.util;
 
 /*-
  * #%L
@@ -52,15 +52,14 @@ public static int parsePositiveInt(final String strNum, int startInclusive, int
         int result = 0;
         try
         {
-
             for (int i = startInclusive; i < endExclusive; i++)
             {
                 final char c = strNum.charAt(i);
                 if (c < ZERO || c > DIGIT_9)
                 {
-                    ErrorUtil.raiseUnexpectedCharacter(strNum, i);
+                    ErrorUtil.raiseUnexpectedCharacter(strNum, i, '0', '1', '2', '3', '4', '5', '6', '7', '8', '9');
                 }
-                result = result * 10 + (c - ZERO);
+                result = (result * 10) + (c - ZERO);
             }
         }
         catch (StringIndexOutOfBoundsException exc)
diff --git a/src/main/java/com/ethlo/time/token/ConfigurableDateTimeParser.java b/src/main/java/com/ethlo/time/token/ConfigurableDateTimeParser.java
new file mode 100644
index 0000000..58246d9
--- /dev/null
+++ b/src/main/java/com/ethlo/time/token/ConfigurableDateTimeParser.java
@@ -0,0 +1,122 @@
+package com.ethlo.time.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import static com.ethlo.time.Field.NANO;
+import static com.ethlo.time.Field.YEAR;
+
+import java.text.ParsePosition;
+import java.time.format.DateTimeParseException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+import com.ethlo.time.DateTime;
+import com.ethlo.time.Field;
+import com.ethlo.time.TimezoneOffset;
+import com.ethlo.time.internal.token.FractionsToken;
+
+public class ConfigurableDateTimeParser implements DateTimeParser
+{
+    private final DateTimeToken[] tokens;
+
+    private ConfigurableDateTimeParser(DateTimeToken... tokens)
+    {
+        final Set<Field> fieldsSeen = new HashSet<>();
+        Arrays.asList(tokens).forEach(t ->
+        {
+            if (t.getField() != null && !fieldsSeen.add(t.getField()))
+            {
+                throw new IllegalArgumentException("Duplicate field " + t.getField() + " in list of tokens: " + Arrays.toString(tokens));
+            }
+        });
+        this.tokens = tokens;
+    }
+
+    public static DateTimeParser of(DateTimeToken... tokens)
+    {
+        return new ConfigurableDateTimeParser(tokens);
+    }
+
+    @Override
+    public DateTime parse(String text, ParsePosition parsePosition)
+    {
+        try
+        {
+            return doParse(text, parsePosition);
+        }
+        catch (DateTimeParseException exc)
+        {
+            parsePosition.setIndex(exc.getErrorIndex());
+            parsePosition.setErrorIndex(exc.getErrorIndex());
+            throw exc;
+        }
+    }
+
+    private DateTime doParse(String text, ParsePosition parsePosition)
+    {
+        int fractionsLength = 0;
+        int highestOrdinal = YEAR.ordinal();
+        final int[] values = new int[]{0, 1, 1, 0, 0, 0, 0, -1};
+
+        for (DateTimeToken token : tokens)
+        {
+            final int index = parsePosition.getIndex();
+            final int value = token.read(text, parsePosition);
+            final Field field = token.getField();
+            if (field != null)
+            {
+                final int ordinal = field.ordinal();
+                values[ordinal] = value;
+                highestOrdinal = Math.max(ordinal, highestOrdinal);
+                if (token instanceof FractionsToken)
+                {
+                    fractionsLength = parsePosition.getIndex() - index;
+                    values[ordinal] = scale(value, fractionsLength);
+                }
+            }
+        }
+
+        return new DateTime(
+                Field.values()[Math.min(highestOrdinal, NANO.ordinal())],
+                values[Field.YEAR.ordinal()],
+                values[Field.MONTH.ordinal()],
+                values[Field.DAY.ordinal()],
+                values[Field.HOUR.ordinal()],
+                values[Field.MINUTE.ordinal()],
+                values[Field.SECOND.ordinal()],
+                values[Field.NANO.ordinal()],
+                values[Field.ZONE_OFFSET.ordinal()] != -1 ? TimezoneOffset.ofTotalSeconds(values[Field.ZONE_OFFSET.ordinal()]) : null,
+                fractionsLength
+        );
+    }
+
+    private int scale(int value, int length)
+    {
+        int pos = length;
+        while (pos < 9)
+        {
+            value *= 10;
+            pos++;
+        }
+        return value;
+    }
+}
diff --git a/src/main/java/com/ethlo/time/token/DateTimeParser.java b/src/main/java/com/ethlo/time/token/DateTimeParser.java
new file mode 100644
index 0000000..b97d441
--- /dev/null
+++ b/src/main/java/com/ethlo/time/token/DateTimeParser.java
@@ -0,0 +1,35 @@
+package com.ethlo.time.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import java.text.ParsePosition;
+
+import com.ethlo.time.DateTime;
+
+public interface DateTimeParser
+{
+    DateTime parse(String text, ParsePosition parsePosition);
+
+    default DateTime parse(String text)
+    {
+        return parse(text, new ParsePosition(0));
+    }
+}
diff --git a/src/main/java/com/ethlo/time/token/DateTimeToken.java b/src/main/java/com/ethlo/time/token/DateTimeToken.java
new file mode 100644
index 0000000..dc7b561
--- /dev/null
+++ b/src/main/java/com/ethlo/time/token/DateTimeToken.java
@@ -0,0 +1,35 @@
+package com.ethlo.time.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import java.text.ParsePosition;
+
+import com.ethlo.time.Field;
+
+public interface DateTimeToken
+{
+    int read(String text, ParsePosition parsePosition);
+
+    default Field getField()
+    {
+        return null;
+    }
+}
diff --git a/src/main/java/com/ethlo/time/token/DateTimeTokens.java b/src/main/java/com/ethlo/time/token/DateTimeTokens.java
new file mode 100644
index 0000000..61ba826
--- /dev/null
+++ b/src/main/java/com/ethlo/time/token/DateTimeTokens.java
@@ -0,0 +1,60 @@
+package com.ethlo.time.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import com.ethlo.time.Field;
+import com.ethlo.time.internal.token.DigitsToken;
+import com.ethlo.time.internal.token.FractionsToken;
+import com.ethlo.time.internal.token.SeparatorToken;
+import com.ethlo.time.internal.token.SeparatorsToken;
+import com.ethlo.time.internal.token.ZoneOffsetToken;
+
+public class DateTimeTokens
+{
+    public static DateTimeToken separators(char... anyOf)
+    {
+        if (anyOf == null || anyOf.length == 0)
+        {
+            throw new IllegalArgumentException("Need at least one separator character");
+        }
+
+        if (anyOf.length == 1)
+        {
+            return new SeparatorToken(anyOf[0]);
+        }
+        return new SeparatorsToken(anyOf);
+    }
+
+    public static DateTimeToken digits(Field field, int length)
+    {
+        return new DigitsToken(field, length);
+    }
+
+    public static DateTimeToken fractions()
+    {
+        return new FractionsToken();
+    }
+
+    public static DateTimeToken zoneOffset()
+    {
+        return new ZoneOffsetToken();
+    }
+}
diff --git a/src/test/java/com/ethlo/time/CharArrayUtilTest.java b/src/test/java/com/ethlo/time/CharArrayUtilTest.java
index ec2505d..931ab7b 100644
--- a/src/test/java/com/ethlo/time/CharArrayUtilTest.java
+++ b/src/test/java/com/ethlo/time/CharArrayUtilTest.java
@@ -26,7 +26,7 @@
 
 import org.junit.jupiter.api.Test;
 
-import com.ethlo.time.internal.LimitedCharArrayIntegerUtil;
+import com.ethlo.time.internal.util.LimitedCharArrayIntegerUtil;
 
 public class CharArrayUtilTest
 {
diff --git a/src/test/java/com/ethlo/time/ParsePositionTest.java b/src/test/java/com/ethlo/time/ParsePositionTest.java
index 8e34738..22f0f03 100644
--- a/src/test/java/com/ethlo/time/ParsePositionTest.java
+++ b/src/test/java/com/ethlo/time/ParsePositionTest.java
@@ -9,9 +9,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
diff --git a/src/test/java/com/ethlo/time/token/ConfigurableDateTimeParserTest.java b/src/test/java/com/ethlo/time/token/ConfigurableDateTimeParserTest.java
new file mode 100644
index 0000000..3cf3e4c
--- /dev/null
+++ b/src/test/java/com/ethlo/time/token/ConfigurableDateTimeParserTest.java
@@ -0,0 +1,223 @@
+package com.ethlo.time.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import static com.ethlo.time.Field.DAY;
+import static com.ethlo.time.Field.HOUR;
+import static com.ethlo.time.Field.MINUTE;
+import static com.ethlo.time.Field.MONTH;
+import static com.ethlo.time.Field.SECOND;
+import static com.ethlo.time.Field.YEAR;
+import static com.ethlo.time.token.DateTimeTokens.digits;
+import static com.ethlo.time.token.DateTimeTokens.fractions;
+import static com.ethlo.time.token.DateTimeTokens.separators;
+import static com.ethlo.time.token.DateTimeTokens.zoneOffset;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.text.ParsePosition;
+import java.time.format.DateTimeParseException;
+
+import org.junit.jupiter.api.Test;
+
+import com.ethlo.time.DateTime;
+import com.ethlo.time.ITU;
+import com.ethlo.time.internal.token.FractionsToken;
+import com.ethlo.time.internal.token.ZoneOffsetToken;
+
+public class ConfigurableDateTimeParserTest
+{
+    private final DateTimeParser rfc3339Parser = DateTimeParsers.of(
+            digits(YEAR, 4),
+            separators('-'),
+            digits(MONTH, 2),
+            separators('-'),
+            digits(DAY, 2),
+            separators('T', 't', ' '),
+            digits(HOUR, 2),
+            separators(':'),
+            digits(MINUTE, 2),
+            separators(':'),
+            digits(SECOND, 2),
+            separators('.'),
+            fractions(),
+            zoneOffset()
+    );
+
+    @Test
+    void parseCustomFormat()
+    {
+        final DateTimeParser parser = DateTimeParsers.of(
+                digits(DAY, 2),
+                separators('-'),
+                digits(MONTH, 2),
+                separators('-'),
+                digits(YEAR, 4),
+                separators(' '),
+                digits(HOUR, 2),
+                digits(MINUTE, 2),
+                digits(SECOND, 2),
+                separators(','),
+                fractions()
+        );
+        final ParsePosition pos = new ParsePosition(0);
+        final String input = "31-12-2000 235937,123456";
+        final DateTime result = parser.parse(input, pos);
+        assertThat(result).isEqualTo(DateTime.of(2000, 12, 31, 23, 59, 37, 123456000, null, 6));
+    }
+
+    @Test
+    void duplicateField()
+    {
+        final IllegalArgumentException exc = assertThrows(IllegalArgumentException.class, () -> DateTimeParsers.of(
+                        digits(HOUR, 2),
+                        separators('a', 'z'),
+                        digits(HOUR, 4),
+                        separators('X')
+                )
+        );
+        assertThat(exc).hasMessage("Duplicate field HOUR in list of tokens: [digits: HOUR(2), separators: [a, z], digits: HOUR(4), separator: X]");
+    }
+
+    @Test
+    void parseRfc3339Format()
+    {
+        final DateTimeParser parser = DateTimeParsers.of(
+                digits(YEAR, 4),
+                separators('-'),
+                digits(MONTH, 2),
+                separators('-'),
+                digits(DAY, 2),
+                separators('T', 't'),
+                digits(HOUR, 2),
+                separators(':'),
+                digits(MINUTE, 2),
+                separators(':'),
+                digits(SECOND, 2),
+                separators('.'),
+                fractions(),
+                zoneOffset()
+        );
+        final String input = "2023-01-01T23:38:34.987654321+06:00";
+        final DateTime fixed = ITU.parseLenient(input);
+
+        final ParsePosition pos = new ParsePosition(0);
+        final DateTime custom = parser.parse(input, pos);
+
+        assertThat(custom).isEqualTo(fixed);
+        assertThat(fixed.toString()).isEqualTo(input);
+        assertThat(custom.toString()).isEqualTo(input);
+    }
+
+    @Test
+    void testInvalidSeparators()
+    {
+        final DateTimeParseException exc = assertThrows(DateTimeParseException.class, () -> DateTimeParsers.of(separators('X')).parse("12"));
+        assertThat(exc).hasMessage("Expected character [X] at position 1, found 1: 12");
+    }
+
+    @Test
+    void testSeparators()
+    {
+        final ParsePosition position = new ParsePosition(0);
+        final int result = separators('-', '_').read("_", position);
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void testInvalidSeparator()
+    {
+        final DateTimeParseException exc = assertThrows(DateTimeParseException.class, () -> DateTimeParsers.of(separators('X')).parse("12"));
+        assertThat(exc).hasMessage("Expected character [X] at position 1, found 1: 12");
+    }
+
+    @Test
+    void testEndOfTextSeparator()
+    {
+        final ParsePosition pos = new ParsePosition(0);
+        final DateTimeParseException exc = assertThrows(DateTimeParseException.class, () -> separators('-').read("", pos));
+        assertThat(exc).hasMessage("Unexpected end of input: ");
+    }
+
+    @Test
+    void reachEndOfFractions()
+    {
+        final int value = new FractionsToken().read("123456X", new ParsePosition(0));
+        assertThat(value).isEqualTo(123456);
+    }
+
+    @Test
+    void readTimeZoneZuluUpper()
+    {
+        final ParsePosition pos = new ParsePosition(0);
+        assertThat(new ZoneOffsetToken().read("Z", pos)).isEqualTo(0);
+    }
+
+    @Test
+    void readTimeZoneZuluLower()
+    {
+        final ParsePosition pos = new ParsePosition(0);
+        assertThat(new ZoneOffsetToken().read("z", pos)).isEqualTo(0);
+    }
+
+    @Test
+    void readTimeZoneUnexpectedChar()
+    {
+        final ParsePosition pos = new ParsePosition(0);
+        final DateTimeParseException exc = assertThrows(DateTimeParseException.class, () -> new ZoneOffsetToken().read("X", pos));
+        assertThat(exc).hasMessage("Expected character [Z, z, +, -] at position 1, found X: X");
+    }
+
+    @Test
+    void readTimeZoneTooShort()
+    {
+        final ParsePosition pos = new ParsePosition(0);
+        final DateTimeParseException exc = assertThrows(DateTimeParseException.class, () -> new ZoneOffsetToken().read("-06:0", pos));
+        assertThat(exc).hasMessage("Invalid timezone offset: -06:0");
+    }
+
+    @Test
+    void readTimeZoneNegative()
+    {
+        final ParsePosition pos = new ParsePosition(0);
+        final int secs = new ZoneOffsetToken().read("-06:30", pos);
+        assertThat(secs).isEqualTo(-23400);
+    }
+
+    @Test
+    void testOffset()
+    {
+        final ParsePosition pos = new ParsePosition(10);
+        final String text = "2019-12-31T22:20:14.123+05:30";
+        rfc3339Parser.parse("123456789," + text + ",something", pos);
+        assertThat(pos.getIndex()).isEqualTo(10 + text.length());
+    }
+
+    @Test
+    void testOffsetError()
+    {
+        final ParsePosition pos = new ParsePosition(10);
+        final String text = "2019-12-31T22:20X14.123+05:30";
+        assertThrows(DateTimeParseException.class, () -> rfc3339Parser.parse("123456789," + text + ",something", pos));
+        assertThat(pos.getIndex()).isEqualTo(26);
+        assertThat(pos.getErrorIndex()).isEqualTo(26);
+    }
+}
diff --git a/src/test/java/com/ethlo/time/token/DateTimeParsers.java b/src/test/java/com/ethlo/time/token/DateTimeParsers.java
new file mode 100644
index 0000000..976ab63
--- /dev/null
+++ b/src/test/java/com/ethlo/time/token/DateTimeParsers.java
@@ -0,0 +1,65 @@
+package com.ethlo.time.token;
+
+/*-
+ * #%L
+ * Internet Time Utility
+ * %%
+ * Copyright (C) 2017 - 2024 Morten Haraldsen (ethlo)
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import static com.ethlo.time.Field.DAY;
+import static com.ethlo.time.Field.HOUR;
+import static com.ethlo.time.Field.MINUTE;
+import static com.ethlo.time.Field.MONTH;
+import static com.ethlo.time.Field.SECOND;
+import static com.ethlo.time.Field.YEAR;
+import static com.ethlo.time.token.DateTimeTokens.digits;
+import static com.ethlo.time.token.DateTimeTokens.fractions;
+import static com.ethlo.time.token.DateTimeTokens.separators;
+
+public class DateTimeParsers
+{
+    private static final ConfigurableDateTimeParser DATE = (ConfigurableDateTimeParser) DateTimeParsers.of(
+            digits(YEAR, 4),
+            separators('-'),
+            digits(MONTH, 2),
+            separators('-'),
+            digits(DAY, 2)
+    );
+    private static final DateTimeParser LOCAL_TIME = of(
+            digits(HOUR, 2),
+            separators(':'),
+            digits(MINUTE, 2),
+            separators(':'),
+            digits(SECOND, 2),
+            fractions()
+    );
+
+    public static DateTimeParser of(DateTimeToken... tokens)
+    {
+        return ConfigurableDateTimeParser.of(tokens);
+    }
+
+    public static DateTimeParser localDate()
+    {
+        return DATE;
+    }
+
+    public static DateTimeParser localTime()
+    {
+        return LOCAL_TIME;
+    }
+}
diff --git a/src/test/resources/test-data.json b/src/test/resources/test-data.json
index ef7f736..26da8c5 100644
--- a/src/test/resources/test-data.json
+++ b/src/test/resources/test-data.json
@@ -91,7 +91,7 @@
     },
     {
         "input": "2020-22-12T12:11.56+04:30",
-        "error": "Unexpected character . at position 17: 2020-22-12T12:11.56+04:30",
+        "error": "Expected character [:, Z, z, +, -] at position 17, found .: 2020-22-12T12:11.56+04:30",
         "error_index": 16
     },
     {
@@ -131,7 +131,7 @@
     },
     {
         "input": "2017-02-21T15:27:22~10:00",
-        "error": "Unexpected character ~ at position 20: 2017-02-21T15:27:22~10:00",
+        "error": "Expected character [., Z, z, +, -] at position 20, found ~: 2017-02-21T15:27:22~10:00",
         "error_index": 19
     },
     {
@@ -181,7 +181,7 @@
     },
     {
         "input": "2017-12-21T12:20:45.9b7Z",
-        "error": "Unexpected character b at position 22: 2017-12-21T12:20:45.9b7Z",
+        "error": "Expected character [Z, z, +, -] at position 22, found b: 2017-12-21T12:20:45.9b7Z",
         "error_index": 21
     },
     {
@@ -231,7 +231,7 @@
     },
     {
         "input": "199g-11-05T08:15:30-05:00",
-        "error": "Unexpected character g at position 4: 199g-11-05T08:15:30-05:00",
+        "error": "Expected character [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] at position 4, found g: 199g-11-05T08:15:30-05:00",
         "error_index": 3,
         "note": "Non-digit in year"
     },