Before and after show the boundary labels at the exact UTC transition. A missing or repeated local label still requires an explicit choice in the planner.
Why an identifier matters
An offset describes one moment. A named zone carries the date-specific rules used to calculate each meeting.
Planning dates run from Thu, Jan 1, 2026 through Mon, Dec 31, 2035. Future rules can be revised; review the data version when a distant schedule matters.
Europe/London resolves a local date and time using the database’s UK rules. It is not interchangeable with a constant UTC+00:00 offset: the January 2026 sample is GMT and the July sample is BST at UTC+01:00. The city page focuses on meeting choices in London; this page explains which rule the software applies.
Offsets in the bundled rules
Sampled at 12:00 UTC on each date, using IANA 2026f.
Date
UTC offset
Display abbreviation
2026-01-15
UTC+00:00
GMT
2026-07-15
UTC+01:00
BST
2026-10-27
UTC+00:00
GMT
2026-11-03
UTC+00:00
GMT
Resolve the wall time before exporting
The local time 01:30 on 29 March 2026 is skipped when the clock moves forward. On 25 October, 01:30 occurs twice. An offset-free wall time in either interval needs a deliberate resolution before it can become an instant.
Use this identifier in a plan
Find Europe/London in the zone directory or choose London from the city directory. Add the other meeting locations, enter their availability, and check the complete duration. The supported planning years are 2026–2035; future political rule changes may require a new data version.
A calendar export uses the resolved UTC start and end times. The zone remains part of the planning context, while the exported instant stays unambiguous when another calendar displays it in its own time zone.