Convert a date string to a timestamp

Convert a date string to a Unix timestamp with GNU date -d 'string' +%s. The zone is the one in TZ unless the string names one, so set it explicitly.

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Summarize in AI

A log line holds a human readable date and you need the number of seconds since 1970 to compare or subtract.

Shell

date -u -d '2026-03-05 14:00:00' +%s
TZ=UTC date -d '2026-03-05 14:00:00' +%s
TZ=Asia/Tokyo date -d '2026-03-05 14:00:00' +%s
date -d '2026-03-05 14:00:00 +0900' +%s

Text

-d parses a date string and %s prints it as epoch seconds, using the grammar in the GNU date manual. Without an explicit offset the string is read in the zone from the TZ variable or the system setting, so the Tokyo run is nine hours earlier than the UTC runs. Naming the offset in the string, as in the last line, removes the dependence on the machine.

This is GNU date. BSD and macOS date do not have -d, and date -j -f is the equivalent there. Strings such as "next friday" are accepted too, but they depend on today's date, so keep them out of scripts that must be reproducible.

Taggeddates linux

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