Add from: parameter to Mel::Job::Every#run_every methods

This is used to specify the first run time.

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Added] - 
+
+### Changed
+- Add `from:` parameter to `Mel::Job::Every#run_every` methods
+
 ## [0.17.2] - 2023-12-04
 
 ### Fixed

README.md

@@ -149,6 +149,14 @@ This makes *Redis* the *source of truth* for schedules, allowing to easily scale
      DoSomeWork.run_every(10.minutes, for: 1.hour, arg_1: 5, arg_2: "value")
      ```
 
+     This will do the first run 10 minutes from now. If you would like to do the first run some other time, specify that in a `from:` argument:
+
+     ```crystal
+     # ->>> src/app/some_file.cr
+
+     DoSomeWork.run_every(10.minutes, from: Time.local, for: 1.hour, arg_1: 5, arg_2: "value")
+     ```
+
      Instead of `for:`, you may use `till:` and specify a `Time`. Leave those out to run forever.
 
    - Run on a Cron schedule:

spec/mel/job/every_spec.cr

@@ -21,6 +21,30 @@ describe Mel::Job::Every do
     Mel::PeriodicTask.find(id).should be_a(Mel::PeriodicTask)
   end
 
+  it "starts at specified time" do
+    address = "user@domain.tld"
+    id = "1001"
+
+    SendEmailEveryJob.run_every(
+      2.hours,
+      from: 10.days.from_now,
+      id: id,
+      address: address
+    )
+
+    Time::Location.local = Time::Location.load("Europe/Berlin")
+
+    Timecop.travel(6.days.from_now) do
+      task = Mel::PeriodicTask.find(id)
+      task.try(&.due?).should be_false
+    end
+
+    Timecop.travel(10.days.from_now) do
+      task = Mel::PeriodicTask.find(id)
+      task.try(&.due?).should be_true
+    end
+  end
+
   it "deletes task after given time" do
     address = "user@domain.tld"
     id = "1001"

src/mel/job/every.cr

@@ -5,27 +5,29 @@ module Mel::Job::Every
     def self.run_every(
       interval : Time::Span,
       for : Time::Span,
+      from : Time? = nil,
       id = UUID.random.hexstring,
       retries = nil,
       redis = nil,
       force = false,
       **job_args
     )
       till = for.from_now
-      run_every(interval, till, id, retries, redis, force, **job_args)
+      run_every(interval, till, from, id, retries, redis, force, **job_args)
     end
 
     def self.run_every(
       interval : Time::Span,
       till : Time? = nil,
+      from : Time? = nil,
       id = UUID.random.hexstring,
       retries = nil,
       redis = nil,
       force = false,
       **job_args
     ) : String?
+      time = from || interval.abs.from_now
       job = new(**job_args)
-      time = interval.abs.from_now
 
       task = Mel::PeriodicTask.new(
         id.to_s,