Make sure that has a timezone (or better still, is explicitly in UTC).
Also, bytes are cheap these days, let's have millisecond precision seconds there too.
Lets go full ISO 8601 and use yyyy-mm-ddThh:mm:ss.sssZ at least this way you have a recognised standard to appeal to if some other code or library can't parse your datetimes.
(One reason I'd accept _not_ using ISO8601 dates is if your database uses a datetime format that's equally human readable and unambiguous, MySQL users might use YYYY-MM-DD hh:mm:ss or YYYY-MM-DD hh:mm:ss.sss with an assumed and well documented UTC timezone.)
Make sure that has a timezone (or better still, is explicitly in UTC).
Also, bytes are cheap these days, let's have millisecond precision seconds there too.
Lets go full ISO 8601 and use yyyy-mm-ddThh:mm:ss.sssZ at least this way you have a recognised standard to appeal to if some other code or library can't parse your datetimes.
(One reason I'd accept _not_ using ISO8601 dates is if your database uses a datetime format that's equally human readable and unambiguous, MySQL users might use YYYY-MM-DD hh:mm:ss or YYYY-MM-DD hh:mm:ss.sss with an assumed and well documented UTC timezone.)