tzdata-legacy 2023c-2exp1ubuntu1 (amd64 binary) in ubuntu mantic

 This package contains data required for the implementation of
 standard local time for many representative locations around the
 globe. It is updated periodically to reflect changes made by
 political bodies to time zone boundaries, UTC offsets, and
 daylight-saving rules.
 .
 This package contains timezones counted in International Atomic Time with a
 -10 second offset (TAI-10s) in /usr/share/zoneinfo/right. This is the current
 IBM recommended setting of hardware clocks on IBM mainframes, which ran on
 GMT until the inception of UTC in 1972 when TAI was 10 seconds ahead of UTC.
 IBM switched to running clocks at the atomic rate and introduced the
 10-second offset in order to avoid a discontinuity.
 .
 You do not need this package if you are unsure.