diff --git a/docs/operator-manual/notifications/functions.md b/docs/operator-manual/notifications/functions.md
index c50d122024b76..ebde62a62afb0 100644
--- a/docs/operator-manual/notifications/functions.md
+++ b/docs/operator-manual/notifications/functions.md
@@ -12,6 +12,44 @@ Golang [Time](https://golang.org/pkg/time/#Time).
 
 Parses specified string using RFC3339 layout. Returns an instance of Golang [Time](https://golang.org/pkg/time/#Time).
 
+<hr>
+Time related constants.
+
+**Durations**
+
+```
+	time.Nanosecond   = 1
+	time.Microsecond  = 1000 * Nanosecond
+	time.Millisecond  = 1000 * Microsecond
+	time.Second       = 1000 * Millisecond
+	time.Minute       = 60 * Second
+	time.Hour         = 60 * Minute
+```
+
+**Timestamps**
+
+Used when formatting time instances as strings (e.g. `time.Now().Format(time.RFC3339)`).
+
+```
+	time.Layout      = "01/02 03:04:05PM '06 -0700" // The reference time, in numerical order.
+	time.ANSIC       = "Mon Jan _2 15:04:05 2006"
+	time.UnixDate    = "Mon Jan _2 15:04:05 MST 2006"
+	time.RubyDate    = "Mon Jan 02 15:04:05 -0700 2006"
+	time.RFC822      = "02 Jan 06 15:04 MST"
+	time.RFC822Z     = "02 Jan 06 15:04 -0700" // RFC822 with numeric zone
+	time.RFC850      = "Monday, 02-Jan-06 15:04:05 MST"
+	time.RFC1123     = "Mon, 02 Jan 2006 15:04:05 MST"
+	time.RFC1123Z    = "Mon, 02 Jan 2006 15:04:05 -0700" // RFC1123 with numeric zone
+	time.RFC3339     = "2006-01-02T15:04:05Z07:00"
+	time.RFC3339Nano = "2006-01-02T15:04:05.999999999Z07:00"
+	time.Kitchen     = "3:04PM"
+	// Handy time stamps.
+	time.Stamp      = "Jan _2 15:04:05"
+	time.StampMilli = "Jan _2 15:04:05.000"
+	time.StampMicro = "Jan _2 15:04:05.000000"
+	time.StampNano  = "Jan _2 15:04:05.000000000"
+```
+
 ### **strings**
 String related functions.
 
diff --git a/go.mod b/go.mod
index 2440ee7c32ec6..2be32c1ffa798 100644
--- a/go.mod
+++ b/go.mod
@@ -9,6 +9,7 @@ require (
 	github.com/Masterminds/sprig/v3 v3.3.0
 	github.com/TomOnTime/utfutil v0.0.0-20180511104225-09c41003ee1d
 	github.com/alicebob/miniredis/v2 v2.33.0
+	github.com/antonmedv/expr v1.15.1
 	github.com/argoproj/gitops-engine v0.7.1-0.20240823213048-95e00254f82a
 	github.com/argoproj/notifications-engine v0.4.1-0.20240606074338-0802cd427621
 	github.com/argoproj/pkg v0.13.7-0.20230626144333-d56162821bd1
@@ -117,7 +118,6 @@ require (
 	github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.1.0 // indirect
 	github.com/Azure/azure-sdk-for-go/sdk/internal v1.0.0 // indirect
 	github.com/AzureAD/microsoft-authentication-library-for-go v0.5.2 // indirect
-	github.com/antonmedv/expr v1.15.1 // indirect
 	github.com/aws/aws-sdk-go-v2 v1.24.1 // indirect
 	github.com/aws/aws-sdk-go-v2/config v1.25.12 // indirect
 	github.com/aws/aws-sdk-go-v2/credentials v1.16.16 // indirect
diff --git a/util/notification/expression/time/time.go b/util/notification/expression/time/time.go
index 6457b75d8c093..63aa31c3d3d13 100644
--- a/util/notification/expression/time/time.go
+++ b/util/notification/expression/time/time.go
@@ -4,10 +4,37 @@ import (
 	"time"
 )
 
+var now = time.Now
+
 func NewExprs() map[string]interface{} {
 	return map[string]interface{}{
+		// Functions
 		"Parse": parse,
 		"Now":   now,
+		// Durations
+		"Nanosecond":  time.Nanosecond,
+		"Microsecond": time.Microsecond,
+		"Millisecond": time.Millisecond,
+		"Second":      time.Second,
+		"Minute":      time.Minute,
+		"Hour":        time.Hour,
+		// Timestamps
+		"Layout":      time.Layout,
+		"ANSIC":       time.ANSIC,
+		"UnixDate":    time.UnixDate,
+		"RubyDate":    time.RubyDate,
+		"RFC822":      time.RFC822,
+		"RFC822Z":     time.RFC822Z,
+		"RFC850":      time.RFC850,
+		"RFC1123":     time.RFC1123,
+		"RFC1123Z":    time.RFC1123Z,
+		"RFC3339":     time.RFC3339,
+		"RFC3339Nano": time.RFC3339Nano,
+		"Kitchen":     time.Kitchen,
+		"Stamp":       time.Stamp,
+		"StampMilli":  time.StampMilli,
+		"StampMicro":  time.StampMicro,
+		"StampNano":   time.StampNano,
 	}
 }
 
@@ -18,7 +45,3 @@ func parse(timestamp string) time.Time {
 	}
 	return res
 }
-
-func now() time.Time {
-	return time.Now()
-}
diff --git a/util/notification/expression/time/time_test.go b/util/notification/expression/time/time_test.go
index 3003521344eb4..a450260bea399 100644
--- a/util/notification/expression/time/time_test.go
+++ b/util/notification/expression/time/time_test.go
@@ -2,19 +2,60 @@ package time
 
 import (
 	"testing"
+	"time"
 
+	"github.com/antonmedv/expr"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestNewTimeExprs(t *testing.T) {
 	funcs := []string{
 		"Parse",
 		"Now",
+		"Nanosecond",
+		"Microsecond",
+		"Millisecond",
+		"Second",
+		"Minute",
+		"Hour",
+		"Layout",
+		"ANSIC",
+		"UnixDate",
+		"RubyDate",
+		"RFC822",
+		"RFC822Z",
+		"RFC850",
+		"RFC1123",
+		"RFC1123Z",
+		"RFC3339",
+		"RFC3339Nano",
+		"Kitchen",
+		"Stamp",
+		"StampMilli",
+		"StampMicro",
+		"StampNano",
 	}
 
 	for _, fn := range funcs {
 		timeExprs := NewExprs()
-		_, hasFunc := timeExprs[fn]
-		assert.True(t, hasFunc)
+		_, exists := timeExprs[fn]
+		assert.True(t, exists)
 	}
 }
+
+func Test_NewExprs_Now(t *testing.T) {
+	defer func() { now = time.Now }()
+	fixedTime := time.Date(2022, 9, 26, 11, 30, 25, 0, time.UTC)
+	now = func() time.Time {
+		return fixedTime
+	}
+
+	vm, err := expr.Compile("time.Now().Truncate(time.Hour).Format(time.RFC3339)")
+	require.NoError(t, err)
+
+	val, err := expr.Run(vm, map[string]interface{}{"time": NewExprs()})
+	require.NoError(t, err)
+
+	assert.Equal(t, "2022-09-26T11:00:00Z", val)
+}