Time vs ActiveSupport::TimeWithZone

0-irb-session-excerpt

irb(main):028:0> cp.last.class
=> Time
irb(main):029:0> cp.last
=> 2022-06-21 15:30:00 -0500
irb(main):030:0> c.next_run.class
=> NilClass
irb(main):031:0> c.next_run=cp.last
=> 2022-06-21 15:30:00 -0500
irb(main):032:0> c.next_run.class
=> ActiveSupport::TimeWithZone
irb(main):033:0> c.next_run
=> Sat, 01 Jan 2000 21:30:00.000000000 UTC +00:00
irb(main):034:0> c.next_run=cp.last
=> 2022-06-21 15:30:00 -0500
irb(main):035:0> c.next_run
=> Sat, 01 Jan 2000 21:30:00.000000000 UTC +00:00
irb(main):036:0>

1-also-tried-to_time

irb(main):063:0> c.next_run=cp.last.to_time
=> 2022-06-21 15:30:00 -0500
irb(main):064:0> c.next_run
=> Sat, 01 Jan 2000 21:30:00.000000000 UTC +00:00
irb(main):065:0>

2-and-this

irb(main):066:0> x.class
=> Time
irb(main):067:0> x
=> 2022-06-21 15:30:00 -0500
irb(main):068:0> c.next_run
=> Sat, 01 Jan 2000 21:30:00.000000000 UTC +00:00
irb(main):069:0> c.next_run=x
=> 2022-06-21 15:30:00 -0500
irb(main):070:0> c.next_run
=> Sat, 01 Jan 2000 21:30:00.000000000 UTC +00:00
irb(main):071:0> ENV{TZ}='UTC'
/home/wwalker/.asdf/installs/ruby/3.1.2/lib/ruby/3.1.0/irb/workspace.rb:119:in `eval': (irb):71: syntax error, unexpected '=', expecting end-of-input (SyntaxError)
ENV{TZ}='UTC'
       ^
irb(main):072:0> ENV['TZ']='UTC'
=> "UTC"
irb(main):073:0> x
=> 2022-06-21 15:30:00 -0500
irb(main):074:0> x=Time.now
=> 2022-06-21 23:43:19.930931468 +0000
irb(main):075:0> c.next_run=x
=> 2022-06-21 23:43:19.930931468 +0000
irb(main):076:0> c.next_run
=> Sat, 01 Jan 2000 23:43:19.930931468 UTC +00:00
irb(main):077:0>

3-model-file

class CreateCrons < ActiveRecord::Migration[7.0]
  def change
    create_table :crons do |t|
      t.string :reminder_id
      t.string :entry
      t.time :last_run
      t.time :next_run
      t.time :deleted_at
      t.string :timestamps

      t.timestamps
    end
  end
end

4-AS::TWZ-is-not-the-culprit

iirb(main):077:0> x=ActiveSupport::TimeWithZone.new(Time.now,Time.zone)
=> Wed, 22 Jun 2022 00:23:02.591031040 UTC +00:00
irb(main):078:0> y=cp.last.to_time
=> 2022-06-21 19:30:00 +0000
irb(main):079:0> x.class
=> ActiveSupport::TimeWithZone
irb(main):080:0> x
=> Wed, 22 Jun 2022 00:23:02.591031040 UTC +00:00
irb(main):081:0> x=y
=> 2022-06-21 19:30:00 +0000
irb(main):082:0> x
=> 2022-06-21 19:30:00 +0000
irb(main):083:0>

5-UTC does not fix it

$ rails c
Loading development environment (Rails 7.0.3)
irb(main):001:0> p ENV['TZ']
"UTC"
=> "UTC"
irb(main):002:0> c=Cron.first!
   (0.7ms)  SELECT sqlite_version(*)
  Cron Load (0.2ms)  SELECT "crons".* FROM "crons" ORDER BY "crons"."id" ASC LIMIT ?  [["LIMIT", 1]]
=>
#<Cron:0x00007f8bcbe68238
...
irb(main):003:0> cp = CronParser.new(c.entry)
=> #<CronParser:0x00007f8bca6d0a08 @source="30 15,19,01 * * *", @time_source=Time>
irb(main):004:0> c.next_run=cp.last.to_time
=> 2022-06-21 19:30:00 +0000
irb(main):005:0> c.next_run
=> Sat, 01 Jan 2000 19:30:00.000000000 UTC +00:00
irb(main):006:0>