Hi, Using date from coreutils 8.31-1 on Arch Linux. This surprised me.
$ TZ=UTC0 /bin/date -d '1pm + 2 hours' Wed 8 May 15:00:00 UTC 2019 $ TZ=UTC0 /bin/date -d '13:00 + 2 hours' Wed 8 May 12:00:00 UTC 2019 The documentation doesn't suggest `1pm' and `13:00' are treated differently. `--debug' helps. $ TZ=UTC0 /bin/date --debug -d '1pm + 2 hours' date: parsed time part: 01:00:00pm date: parsed relative part: +2 hour(s) ... $ TZ=UTC0 /bin/date --debug -d '13:00 + 2 hours' date: parsed time part: 13:00:00 UTC+02 date: parsed relative part: +1 hour(s) date: input timezone: parsed date/time string (+02) ... It looks like parsing is broken in the second case. The result I wanted can also be obtained my omitting the `+'. $ TZ=UTC0 /bin/date -d '1pm 2 hours' Wed 8 May 15:00:00 UTC 2019 $ TZ=UTC0 /bin/date -d '13:00 2 hours' Wed 8 May 15:00:00 UTC 2019 -- Cheers, Ralph.