CET to GMT Converter

Which CET and which GMT?

Zone abbreviations are ambiguous, so this page starts by pinning both down. CET here is Central European Time: the IANA zone Europe/Paris, anchored on Paris. GMT here is Greenwich Mean Time: Europe/London, anchored on London. Note that GMT is also UTC±0 kept year-round, which London does not do; this page means only the London sense.

CET in the everyday sense means Paris time, whichever of CET or CEST (Central European Summer Time) is in force. Paris is not on CET all year: its offset is UTC+1 while standard time applies (its January offset) and UTC+2 while daylight saving is active (its July offset). As of September 2026 it is on CEST (UTC+2). Wherever this page writes CET, read it as "Paris time on the date in question".

GMT in the everyday sense means London time, whichever of GMT or BST (British Summer Time) is in force. London is not on GMT all year: its offset is UTC±0 while standard time applies (its January offset) and UTC+1 while daylight saving is active (its July offset). As of September 2026 it is on BST (UTC+1). Wherever this page writes GMT, read it as "London time on the date in question".

The difference as of September 2026

As of September 2026, London is 1 hour behind Paris. Paris is on UTC+2 (CEST, daylight saving in effect) and London is on UTC+1 (BST, daylight saving in effect). Subtract one offset from the other and you have the gap. As wall clocks: 9:00 AM in Paris is 8:00 AM in London, 5:00 PM in Paris is 4:00 PM in London, and 9:00 AM in London is 10:00 AM in Paris.

Next scheduled clock changes: clocks in Paris go back 1 hour on Sunday, October 25, 2026 (local date), moving the offset from UTC+2 to UTC+1; clocks in London go back 1 hour on Sunday, October 25, 2026 (local date), moving the offset from UTC+1 to UTC±0. Neither change moves the gap, because the other side changes on the same date.

How the gap changes through the year

Both Paris and London observe daylight saving — Paris moves between UTC+1 and UTC+2, London between UTC±0 and UTC+1 — yet the gap between them never moves from one day to the next. Across the whole year scanned from Sep 7, 2026, the engine finds one unbroken run: London is 1 hour behind Paris throughout.

The reason is that the two sides switch on the same dates. When clocks in Paris go forward by 1 hour, clocks in London go forward by 1 hour on the same day, so the two offsets rise together and their difference is unchanged; the same happens in reverse when both fall back. The scan confirms it: there is no day in the year ahead on which one side has switched and the other has not. The next such shared date, as of September 2026: clocks in Paris go back 1 hour on Sunday, October 25, 2026 (local date), moving the offset from UTC+2 to UTC+1, and clocks in London go back 1 hour on Sunday, October 25, 2026 (local date), moving the offset from UTC+1 to UTC±0.

This is why the pair feels simple — you can remember one number and it holds. It is also why that simplicity is conditional rather than structural. The gap is fixed only because both sides keep the same daylight-saving calendar. If either side changed its rules, whether by moving its dates or by stopping the seasonal shift altogether, the pair would immediately acquire a second gap for part of the year, exactly like the pairs on this site where only one side shifts. Nothing on this page assumes that will not happen: the schedule is recomputed from the tz database on every build, so a rule change would show up here as a new row rather than a stale number.

Working hours that overlap

Assume a 9:00 AM to 5:00 PM day on both sides. The gap never changes, so the overlap is the same all year:

• London 1 hour behind Paris (CEST / BST or CET / GMT; 365 of the 365 days scanned): 7 hours of shared working time: 10:00 AM to 5:00 PM in Paris, which is 9:00 AM to 4:00 PM in London.

The 9-to-5 window is a convention, not a fact about anyone's real hours. The Meeting Planner lets you set each side's actual working hours and shows the overlap for the exact date you are planning.

Converting GMT to CET

This page serves both directions, because the reverse conversion is the same gap with the sign flipped. As of September 2026, Paris is 1 hour ahead of London, so:

• 9:00 AM CET (Paris) = 8:00 AM GMT (London)
• 9:00 AM GMT (London) = 10:00 AM CET (Paris)
• 5:00 PM GMT (London) = 6:00 PM CET (Paris)

To run GMT to CET in the converter above, swap the From and To menus; the result shows both offsets for the date you enter and flags a day change whenever the reading lands on the previous or next calendar day. Because the gap never moves, these readings hold in every season.

More on these zones

• Current time in Paris — live clock, offset and next clock change.
• Current time in London — live clock, offset and next clock change.
• Time Zone Converter — any city to any city, DST-correct for the date.
• Meeting Planner — overlap for your real working hours.
• All zone-to-zone converters — the other corridors on this site.

CET to GMT — frequently asked questions

Conversions are computed locally in your browser from its IANA time zone data; nothing you enter is transmitted. The schedule and offsets on this page were derived from the same database at build time, as of September 2026. Jurisdictions occasionally change DST law with short notice, and the IANA database follows reality — for legally critical timing, confirm against an official source. See the methodology page.