Europe/Dublin

TZ identifier and aliases

Europe/Dublin is the canonical identifier for Irish civil time. Eire is an older name still pointing at the same rules but is a deprecated alias — use Europe/Dublin in new code.

UTC offset and DST rule

This is the one zone in this batch where "standard" and "DST" are legally inverted from how every other country defines them. Europe/Dublin is +01:00 (Irish Standard Time) in summer and +00:00 (a legally-defined winter exception) from the last Sunday in October to the last Sunday in March — the same clock-change dates as every other EU zone, just with the labels swapped. Computationally the offset behaves identically to Europe/London: +00:00 from late October to late March, +01:00 the rest of the year.

Using it in cron, CI and Postgres

Set TZ=Europe/Dublin for a process that should schedule by Irish local time — note that some libraries surface the IANA database's DST flag directly, and because Ireland's "standard time" is legally the summer offset, code that assumes "DST flag true" always means "ahead of the country's legal standard" can get the label backwards even though the actual UTC offset is correct either way. Postgres accepts it via SET TIME ZONE 'Europe/Dublin'; or the timezone setting. Where a scheduler supports a CRON_TZ=Europe/Dublin line, jobs run by local time directly; GitHub Actions' schedule: trigger always evaluates in UTC, so a fixed-local-hour job needs its UTC equivalent updated across each transition. Avoid the 1:00–2:00am local window for anything that must run exactly once.

History and quirks

Ireland's Standard Time Act 1968 declared that "the time for general purposes in the State (to be known as standard time) shall be one hour in advance of Greenwich mean time throughout the year" — legally making +01:00 the country's standard time. When Ireland reintroduced seasonal clock changes in 1971 ahead of joining the EEC, lawmakers didn't rewrite that language; they simply added a winter exception during which the country legally operates at GMT instead of its own "standard" time. The practical result: Ireland is the only country in this family where winter, not summer, is the clock-change exception in the letter of the law, even though the actual times observed are identical to the UK's. It's a purely legal curiosity rather than a computational one — every date library and the IANA database itself track Europe/Dublin's offsets the same way any other zone's are tracked, with no special handling required.

Offsets and DST transitions on this page are computed from the IANA time zone database bundled with your browser; the rules described above were verified against tzdata 2026b when this page was published.