Central European Time to Greenwich Mean Time.
CET to GMT conversion table
Every hour of today in CET with the matching time in GMT. Rows in the shaded band are working hours (9 AM to 6 PM) in both zones, the best slots for a call.
About the two zones
CET: Central European Time covers Paris, Berlin, Madrid, Rome and Amsterdam. It is UTC+1 in winter (CET) and UTC+2 in summer (CEST).
GMT: GMT is UTC+0, the winter time in the UK, Ireland and Portugal. In summer the UK moves to BST (UTC+1).
Reverse it: GMT to CET. Compare either against UTC or see the full converter.
Questions
Will the alarm ring if I close the tab or the laptop?
No. No website can ring after the browser is closed or the computer sleeps. Keep this tab open, plug in, and the clock keeps the screen awake for you. The Ready-to-ring check under the clock shows what is set up correctly.
Does it work on my phone?
Yes on Android while the tab is open (behind other tabs is fine). On iPhone the page must stay in the foreground because Safari does not let web pages play sound from the background. Add it to the Home Screen for a full-screen bedside clock.
Is it loud enough for heavy sleepers?
Pick Loud buzzer or Siren, set the volume slider to full, and switch on the sums-to-stop option in Settings so the alarm cannot be dismissed half asleep. The sunrise light brightens the screen before the alarm too.
Can I use my own sound?
Yes. In Settings, choose an MP3, WAV or OGG file. It is stored in this browser only and never uploaded. There are also 60 built-in sounds, from a twin-bell alarm clock and a rooster to an air horn and a music box, on the sounds page.
What do the sleep sounds do?
Rain, brown noise, white noise, fan and ocean are generated in the browser and play until the alarm, then fade out as it rings. They keep the tab active through the night.
Does it need an internet connection?
Only to load the page the first time. Alarms, sounds, the sleep calculator and the sunrise math all run on your device, and the page works offline once it has been opened.
Is anything stored or sent?
Alarms and settings are saved in your browser's local storage. Nothing is sent to a server, and there is no account.
How many hours ahead or behind is GMT from CET?
The difference is shown live above and changes when either zone enters or leaves daylight saving; the converter always uses today's offsets.
What is the best time for a call between CET and GMT?
Look for shaded rows in the table: those hours are between 9 AM and 6 PM in both zones. If there are none, one side has to take an early or late call; the table shows exactly how early.