Comment 4 for bug 1464051

I can also confirm this behavior

$ at -t 202012140849.27
warning: commands will be executed using /bin/sh
at> date > /tmp/testme
at> <EOT>
job 2 at Mon Dec 14 08:49:00 2020

$ cat /tmp/testme
Mo 14. Dez 08:49:00 CET 2020

So it announces AND executes ignoring the seconds.

That code is in since 3.1.11 by upstream which was the time that -t was added.

Seconds are only used in "-t option" -> "posixtime" -> "posixtime_time_parse" which is called before seconds are dropped intentionally.

This isn't a regression it always was a missing detail from upstream that never worked.
Note: this is the same as https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=792040
Adding that as tracker.

The change got now implemented by upstream in:
https://salsa.debian.org/debian/at/-/commit/15ee22de9dfd67d9c97404302623a9d45ce887a2

This was meant to be in 3.1.24, but that got never released.
It got into 3.2.0 which is a bigger step and not yet packaged/uploaded for Debian/Ubuntu (there is 3.2.1 already).

I'll subscribe paride who was recently merging "at" to consider getting this updated.