Search for the intended place
Use Add a city and search a city name, a supported alias, or an exact IANA identifier. The curated city list has 32 locations; the bundled zone database provides additional named identifiers. Choose the intended result and check the zone displayed with it. A search alias refers to the same entity, not a separate time rule.
Keep two to eight rows
A plan compares at least two and at most eight distinct selected city or zone identifiers. Remove a row before adding a ninth. Reorder rows to make the comparison easier to read. The anchor must remain one of the selected locations; choose another anchor before removing the current one.
Understand a shared rule identifier
Mumbai and New Delhi both use Asia/Kolkata. Shanghai and Beijing both use Asia/Shanghai. Their city labels still identify different participants. You can keep both rows and give them different working days or hours, even when the clock output matches.
Conversely, two different named zones may have the same offset on a selected date and differ later. Vancouver and Los Angeles match on 27 October 2026 but differ in the November sample under IANA 2026f. Preserve the correct named location in the plan.
Change the anchor deliberately
When changing the anchor city, choose Keep the same moment to preserve the instant and update the new anchor’s local date and clock time. Choose Keep the same local time to preserve the written date and time, resolving a potentially different instant under the new anchor’s rules. Review any resulting missing or repeated-time warning.
When a location is not listed
Search the exact appropriate IANA identifier if you know it. Avoid substituting a nearby city solely because its clock matches today. If the correct rules are not bundled, do not treat an approximate fixed offset as a verified future conversion. The data-sources guide explains the bundled version and limits.
Sources
Follow the original references for the rules and formats used in this guide.