How many hours is CET ahead of ADT?
As abbreviations, ADT is always 4 hours behind of CET: CET is UTC+1 and ADT is UTC−3. To convert, subtract 4 hours.
Check which label you actually need: ADT (Atlantic Time is on AST today). A time written with an abbreviation that is not in use is usually meant as the local time, so convert between the places instead: right now ADT is 5 hours behind of CET.
When the CET to ADT time difference changes
For most of the year ADT is 5 hours behind of CET. From 14 March to 27 March 2027, ADT is 4 hours behind of CET instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
| Dates | ADT vs CET | Length |
|---|---|---|
| 1 November 2026 to 31 December 2026 | 5 hours behind | 61 days |
| 1 January 2027 to 13 March 2027 | 5 hours behind | 72 days |
| 14 March 2027 to 27 March 2027 | 4 hours behind | 14 days |
| 28 March 2027 to 30 October 2027 | 5 hours behind | 217 days |
| 31 October 2027 to 6 November 2027 | 4 hours behind | 7 days |
| 7 November 2027 to 31 December 2027 | 5 hours behind | 55 days |
Calling hours for CET and ADT
- When ADT is 5 hours behind of CET: 3 shared office hours, 14:00 to 17:00 in CET (09:00 to 12:00 in ADT).
- When ADT is 4 hours behind of CET: 4 shared office hours, 13:00 to 17:00 in CET (09:00 to 13:00 in ADT).