List of tz database time zones

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".

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".