Where does the time-zone information come from?
Offsets and daylight-saving transitions are calculated from the IANA time zone database. Place information is matched to those zones using geographic source data.
Why can the displayed clock differ from another device?
The page uses the viewing device's clock. A device that has stopped synchronizing can be early or late even when its selected time zone is correct.
Are future daylight-saving dates guaranteed?
Future transitions reflect the rules currently published in the time-zone database. Governments can change those rules, so recheck important future plans closer to the date.
Can this site replace an official schedule?
No. Use the site for planning and comparison, then confirm legal deadlines, transport departures and market sessions with the responsible authority.