Time Zones FAQs

Information regarding IANA time zones, offsets, and abbreviations.

UTC vs GMT FAQs

What is the difference between UTC and GMT?

Why is UTC used as the global time standard?

Is London always on GMT?

What does "Zulu Time" mean?

Daylight Saving (DST) FAQs

What is the purpose of Daylight Saving Time?

When do the clocks "spring forward" and "fall back"?

Which countries or states do not observe DST?

Does Daylight Saving Time actually save energy?

How does the time change affect our sleep and health?

Offsets & Conversion FAQs

What does a time zone "offset" mean?

How do I calculate the time difference between two cities?

Why do some countries have a 30-minute or 45-minute offset?

What time zone is UTC-5?

International Date Line FAQs

What happens when you cross the International Date Line?

Where does the day officially start first?

Can two places be 26 hours apart in time?

Why is the International Date Line not a straight line?

Abbreviations FAQs

What do abbreviations like EST, PST, and CET stand for?

What is the difference between "Standard" and "Daylight" abbreviations?

Is "ET" the same as "EST"?

How many time zones are there in the world?