Technical Specifications & Standards
Official chronometric properties, ISO standards, and international database registry identifiers for Western European Summer Time:
Daylight Saving Time (DST) Transitions
⬆️ Spring Forward (Clocks Advance)
Last Sunday in March at 01:00 AM UTC (Clocks advance from WET to WEST)
⬇️ Fall Back (Clocks Return)
Last Sunday in October at 02:00 AM UTC (Clocks return from WEST to WET)
Observing Jurisdictions & Subdivisions
5 Sovereign NationsSovereign nations, administrative subdivisions, and regional territories officially operating under WEST:
Regional Subdivisions & Territory Details
Financial Markets & Trading Hours
During summer months, Lisbon operates on the same UTC+1 offset as London and Dublin, facilitating synchronized equity and bond auctions.
Local Hours: 08:00 - 16:30 WEST
UTC Window: 07:00 - 15:30 UTC
Major Cities in WEST
Primary metropolitan centers and financial hubs observing this time zone:
Adoption History & Astronomical Facts
Year Established: 1977
Portugal instituted summer time regularly following the 1973 European oil shock, harmonizing its daylight transition schedules with the European Union directives that took full effect in the early 1980s.
Because the western coastline of mainland Portugal sits at roughly 9° West longitude, midsummer sunsets in seaside towns like Cascais or Nazaré frequently linger past 09:15 PM under Western European Summer Time.
Frequently Asked Questions about WEST
What is the difference between WEST and WET?
WEST is the summer daylight saving variant of Western European Time, advancing clocks by one hour from UTC+0 to UTC+1 between late March and late October.
Is WEST the same as British Summer Time (BST)?
Yes. Both WEST and BST share the exact same UTC+1 offset and execute their daylight saving changes on the identical Sunday morning according to European Union protocol.
Does WEST match Central European Time (CET)?
Yes in numerical offset (both are UTC+1), but CET is winter standard time for countries like France and Germany. When Portugal is on WEST, Central Europe has already moved forward to CEST (UTC+2).