If you've ever found the time difference between two places had mysteriously shifted by an hour, daylight saving time is usually the culprit. Here's how it and time zones work, and why it matters for travel.
How Time Zones Work
The world is divided into time zones, roughly following longitude, so that clocks align with the sun. They're measured as offsets from Coordinated Universal Time (UTC). Political boundaries and half-hour offsets (like India's UTC+5:30) make the real map more complex than a neat grid.
What Daylight Saving Time Does
Many countries shift their clocks forward by an hour in spring and back in autumn to make better use of evening daylight. Crucially, not all countries observe it, and those that do change on different dates — so the time difference between two places can vary several times a year.
Why It Matters for Travel
- The time difference you plan around may change depending on travel dates.
- Some places (e.g. most of Arizona, and many equatorial countries) don't observe DST at all.
- Always confirm the current local time difference for your exact dates.
- Flight and connection times can be affected around DST changeover dates.
Frequently Asked Questions
Because of daylight saving time. Many countries shift their clocks by an hour in spring and autumn, but not all observe it and those that do change on different dates. This means the time difference between two places can vary several times a year.