[deepsun]

Improvement idea -- in my experience "valid_from" is always a date (no time, no timezone). That's how it's reported in documents (e.g. contract validity period).

Rows that need seconds (e.g. bank transactions) are events, they aren't "valid" from a particular point in time forward, they just happen.

[nine_k]

In my experience, validity time may start at the start of business day, and likely has a specific time zone. In particular, I've seen how documents related to stock trading at NASDAQ specify Eastern Standard Time as the applicable timezone.

I understand how convenient it is to use UTC-only timestamps. It works in most cases but not all.

[adammarples]

No point losing information like that. What do you do if someone opens and closes an account on the same day? Changes their email address three times in one day? Etc

[deepsun]

Agree, if your updates have time then datetime it should be. It's just in my work everything is date only. E.g. employment starts on a date, not datetime, there's no data loss.