Technical Specifications & Standards
Official chronometric properties, ISO standards, and international database registry identifiers for Azores Summer Time:
Daylight Saving Time (DST) Transitions
⬆️ Spring Forward (Clocks Advance)
Last Sunday in March at 00:00 midnight (Clocks advance from AZOT to AZOST)
⬇️ Fall Back (Clocks Return)
Last Sunday in October at 01:00 AM (Clocks return from AZOST to AZOT)
Observing Jurisdictions & Subdivisions
1 Sovereign NationsSovereign nations, administrative subdivisions, and regional territories officially operating under AZOST:
Regional Subdivisions & Territory Details
Financial Markets & Trading Hours
When AZOST is active, Azores banking and aviation coordination aligns perfectly with the standard zero-offset baseline of London and UTC.
Local Hours: 08:00 - 15:30 AZOST
UTC Window: 08:00 - 16:30 UTC
Major Cities in AZOST
Primary metropolitan centers and financial hubs observing this time zone:
Adoption History & Astronomical Facts
Year Established: 1977
Adopted to keep the archipelago's internal transport and trade synchronized with mainland Portugal and the European Economic Community following the 1970s global energy crisis.
When the Azores observes summer daylight saving time (AZOST), its clocks read the exact same hour and minute as Greenwich Mean Time (GMT) and Coordinated Universal Time (UTC).
Frequently Asked Questions about AZOST
What is the difference between AZOST and AZOT?
AZOST (Azores Summer Time, UTC+0) is the summer daylight saving variant of Azores Standard Time (AZOT, UTC-1). Clocks advance by one hour between late March and late October.
Is the Azores on UTC+0 during summer?
Yes. When the clocks jump forward by one hour in late March, the Azores sits on UTC+0, sharing the same clock time as Reykjavik, Iceland, and Accra, Ghana.
What is the time difference between the Azores and Lisbon in summer?
The Azores is always one hour behind Lisbon. In summer, the Azores is on AZOST (UTC+0) while Lisbon is on WEST (UTC+1).