There is no overlap between 09:00–18:00 working days in these two places.
How many hours is CET ahead of HST?
As abbreviations, HST is always 11 hours behind of CET: CET is UTC+1 and HST is UTC−10. To convert, subtract 11 hours.
When the CET to HST time difference changes
For most of the year HST is 12 hours behind of CET. From 25 October to 31 December 2026, HST is 11 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
HST vs CET
Length
25 October 2026 to 31 December 2026
11 hours behind
68 days
1 January 2027 to 27 March 2027
11 hours behind
86 days
28 March 2027 to 30 October 2027
12 hours behind
217 days
31 October 2027 to 31 December 2027
11 hours behind
62 days
When CET and HST are both at work
When HST is 12 hours behind of CET: no shared 09:00 to 17:00 hours; try 19:00 in CET (07:00 in HST).
When HST is 11 hours behind of CET: no shared 09:00 to 17:00 hours; try 18:00 in CET (07:00 in HST).
Frequently asked questions about CET and HST time
How many hours ahead is HST of CET?
HST (UTC−10) is 11 hours behind of CET (UTC+1).
Does the time difference between CET and HST change?
Yes. It is usually 12 hours behind, but changes when one side moves its clocks: 11 hours behind from 25 October to 31 December 2026; 11 hours behind from 1 January to 27 March 2027.