One note on this subject - I migrated from using Timex to using naive datetimes when I upgraded after reading this thread. My services started erroring with data from my frontend that had been working prior to the upgrade. I use postgres for the database. timestamps were fine. the problem was in fields like ‘appointment datetime’ - my frontend JS datetime pickers were not sending seconds ie “2018-12-12T16:00” was sent - and the cast in my models was returning invalid date format errors. iso 8601 does not mandate seconds from what I read - but NaiveDateTime.from_iso8601 throws the exception, and the Timex usage/implementation did not error. So I rolled my ownNaiveDateTimeNoSeconds Ecto type to deal with this.
