Reference
Roughly a third of the world's countries still shift their clocks twice a year — the rest either never did, or abolished it. Here's the current regional picture.
Daylight saving rules change by legislation, sometimes with little notice — the US Congress and the EU have both had active, ongoing debates about ending clock changes entirely in recent years, without a final resolution taking effect yet as of this page's last update. Treat this as the current regional pattern, not something guaranteed to stay this way, and check the DST Change Tracker for exact upcoming change dates in your own zone.
Most of Europe, North America (US, Canada, parts of Mexico), and a handful of countries elsewhere still observe it. Nearly all of Africa, most of Asia, and most of South America do not — largely because countries closer to the equator see little seasonal daylight variation, making the practice pointless there. Australia and a few southern-hemisphere countries observe it only in some states or regions, not nationwide.
Related
Exact upcoming clock-change dates for your specific zone.
Check any specific zone's current offset and rules directly.
The technical side of what these clock changes break.