This is a list of time zones from release 2025c of thetz database.^[2]

• Canonical – The primary, preferred zone name.
• Link – An alternative name (alias) which links to a canonical zone.
• Link^†
   – A standard Link (as above). The dagger symbol (†) signifies that the zone was canonical in a previous version of the database. Historical data for such zones is still preserved in the source code, but it is not included when compiling the database with standard options.

Standard Time (SDT) andDaylight Saving Time (DST) offsets fromUTC in hours and minutes.
For zones in which Daylight Saving is not observed, the DST offset shown in this table is a simple duplication of the SDT offset.
The UTC offsets are based on the current or upcoming database rules. This table does not attempt to document any of the historical data which resides in the database.

In Ireland, what Irish law designates as "standard time" is observed during the summer, with clocks turned one hour ahead of UTC.^[3][4] The SDT column shows the offset from UTC during the winter, even in Ireland, where that's referred to as "winter time", and the DST column shows the offset from UTC during the summer, even in Ireland, where that's referred to as "standard time".

Time zone abbreviations for both Standard Time and Daylight Saving Time are shown exactly as they appear in the database. Seestrftime and its "%Z" field.
Some of zone records use 3 or 4 letter abbreviations that are tied to physical time zones, others use numeric UTC offsets.

In Ireland, what Irish law designates as "standard time" is observed during the summer, with clocks turned one hour ahead of UTC.^[3][4] The SDT column shows the abbreviation used during the winter, even in Ireland, and the DST column shows the abbreviation used during the summer, which is "IST", where the "S" in "IST" stands for "Standard", not "Summer".

Legend:  Canonical  Link