Time zone · Antarctic
TST
Troll Summer Time
Troll Summer Time (UTC+02:00) is used only at Norway's Troll research station in Antarctica. From the last Sunday of March to the last Sunday of October, the station moves its clocks two hours ahead of its standard time (UTC+00:00), in step with Norway's summer time. That period falls mostly in the southern autumn and winter, so the change follows Norway's calendar rather than local daylight.
Thursday, October 15, 2026
Current offset
UTC+02:00
Daylight · +02
Daylight saving
Active
Reverts 25 Oct 2026
IANA zones
1
1 observe DST, 0 don't
DST offset
—
No summer variant
About TST
Standard time, with a summer shift.
Troll Summer Time (UTC+02:00) is used only at Norway's Troll research station in Antarctica. From the last Sunday of March to the last Sunday of October, the station moves its clocks two hours ahead of its standard time (UTC+00:00), in step with Norway's summer time. That period falls mostly in the southern autumn and winter, so the change follows Norway's calendar rather than local daylight.
IANA zones · the technical identifiers
The zone that resolve to TST.
For software, always store the IANA identifier — never the abbreviation alone. The database keeps these zones distinct because their rules can, and historically did, diverge.
Where TST is used
One country.
Same offset · UTC+02:00
Other zones at UTC+02:00 right now.
These named zones share TST's offset today. When daylight saving rules differ, they drift apart for part of the year.
Convert
TST to the world's clocks.
Frequently asked questions
Common questions about TST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- Why does Troll use UTC+02 in summer?
- Troll switches to UTC+02:00 on the same dates Europe starts summer time, so from late March to late October its clocks match Norway's (Central European Summer Time). The rest of the year it uses UTC+00:00, one hour behind Norway.
- TST has only one member zone?
- Yes. Troll station is the only place that uses Troll Summer Time. It switches between UTC+00:00 and UTC+02:00 each year on the European Union's summer-time dates.
- Why is there nearly 24-hour sunlight at Troll?
- Troll station is at about 72°S, south of the Antarctic Circle, so it has continuous daylight around the December solstice and polar night around the June solstice. Its UTC+02:00 setting is used from late March to late October, mostly the southern autumn and winter, not the period of 24-hour sunlight.
- Antarctica has no native population — why the 'time zone?
- Research stations keep time for logistics. Troll uses UTC+00:00 during the European winter and UTC+02:00 during the European summer, changing its clocks on the same dates as Norway, its home country. It is one hour behind Norway in winter and on the same time in summer.
- When does Troll Summer Time end?
- On the last Sunday of October, clocks go back from UTC+02:00 to UTC+00:00. Troll Summer Time starts again on the last Sunday of March.
Source: IANA tzdb2026d · Reviewed
Free · Developer API
This time zone, as JSON.
Its defining offset, DST status and member counts, from one endpoint.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
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