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Back to the catalogueTime-zone databaseCase 05 of 06
Timezone-database vintage mismatch
The IANA tz database is released roughly ten times a year for political changes. Two systems on different releases resolve the same (wall time, zone) to different UTC instants near a changed transition — the temporal analog of a boundary-vintage mismatch in geo.
Class
Case to account for
Affects
3 conversions
01
Detection
Compare the tzdb version recorded in each system's provenance.
02
Mitigation
01
Pin and RECORD the tzdb version on every conversion (requested vs executed).
02
Re-resolve affected wall times when the tzdb is bumped.
03
Affected conversions
Timestamp + zonehour-of-week slot
OPENBroadcast day (declared cutover) ⇄ slot-set
OPENDaypart (local band) ⇄ UTC slot-set
OPEN