What is daylight saving time?
Daylight saving time (DST) is the practice of setting clocks forward by one hour during summer months so that evenings have more daylight. Not all countries observe it — for example China, India, Japan and most of Africa do not change their clocks.
In the Northern Hemisphere, clocks typically go forward in March or April and back in October or November. In the Southern Hemisphere (Australia, New Zealand, South America) the pattern is reversed — forward in October and back in April.
The exact dates vary by country and change year to year. WorldClock.International always shows the correct current time regardless of DST.
Frequently Asked Questions
What is daylight saving time?+
Daylight saving time (DST) is the practice of setting clocks forward by one hour during the summer months so that evenings have more daylight. Clocks go forward in spring and back in autumn.
Do all countries observe daylight saving time?+
No. Many countries do not observe DST including China, India, Japan, South Korea, Singapore, the UAE, Saudi Arabia, most of Africa, and Iceland. Countries near the equator tend not to observe it as their day length barely changes throughout the year.
When do clocks change in the UK?+
In the UK, clocks go forward one hour on the last Sunday in March (to BST, UTC+1) and back one hour on the last Sunday in October (to GMT, UTC+0).
When do clocks change in the USA?+
In the USA, clocks go forward on the second Sunday in March and back on the first Sunday in November. Not all US states observe DST — Arizona (except the Navajo Nation) and Hawaii do not change their clocks.
Why does the EU observe daylight saving time on different dates to the USA?+
The EU and USA both use the last and first Sunday rules but in different months — the EU changes in late March and late October, while the USA changes in mid-March and early November. This creates a period each year where the time difference between European and American cities is one hour different to usual.