Dublin

Ireland • Greenwich Mean Time / Irish Standard Time

Time Zone

Dublin uses Greenwich Mean Time / Irish Standard Time (GMT / IST), currently running at UTC+0 (winter) / UTC+1 (summer). Ireland uniquely defines its standard time as UTC+1 (Irish Standard Time) and treats winter GMT as the seasonal adjustment — the practical clock-change dates match the UK's, in late March and late October.

Business & Commerce

Dublin operates on Greenwich Mean Time (GMT, UTC+0) in winter and Irish Standard Time (IST, UTC+1) in summer — the same practical clock as London, though Ireland's legal framework technically defines IST as the baseline and treats winter GMT as the temporary adjustment. Dublin is the European headquarters city for a striking share of major U.S. technology and pharmaceutical companies, including Google, Meta, Apple, and numerous life-sciences firms, drawn by English-language business operations, EU market access, and favorable tax treatment. This concentration means Dublin's business day is in constant, high-volume coordination with both U.S. West Coast headquarters (evening overlap) and continental European offices (full daytime overlap). At UTC+0/+1, Dublin keeps the same clock as London and is typically five hours ahead of New York in winter.