Guides

Everything we write that is longer than a clock lives here: 51 guides in 8 sections, covering how time zones are drawn, what daylight saving actually does to them, how to schedule across the resulting mess, how to travel through it, and the astronomy the whole system rests on in the end.

These are written and edited by us rather than assembled from feeds, and they are revised in place: when a country changes its clock rules, the guide covering it changes too instead of being left to age. Nothing in them is a paid mention, and where a guide links to one of our city clock pages it is because a live figure is the useful next step, not because the link was sold.

How to use them

If you are trying to arrange something with people in another country, start with How to Schedule Meetings Across Time Zones for the method, then take the Business & Remote Work guide that matches your corridor for the hour-by-hour overlap.

If you are about to travel, the Travel section is about the part of the journey that continues after you land, beginning with How to Beat Jet Lag.

If you have arrived from a clock page and simply want to know what an offset or an abbreviation such as BST means, read What Is UTC and Why Is It Important? followed by Time Zone Abbreviations Explained. If the answer you need is seasonal, the Daylight Saving Time section covers the weeks of the year when the usual offsets stop applying.