UtilToolkits2025-12-26
TL;DR — The Timezone Converter shows side-by-side time across any cities, with a draggable slider to find the overlap window. Pair with the World Clock for an always-on dashboard, and the Date Calculator for "how many business days away."
If your team is spread across SF, Berlin, Bangalore, and Tokyo, you have at most a 1-hour overlap where everyone is in working hours. Daylight Saving Time changes that gap by an hour for a few weeks each spring and fall — and not on the same dates. The result: a calendar full of misaligned invites, missed meetings, and the eternal "is that EST or EDT?" thread.
| IANA (always use this) | Common abbreviation | UTC offset |
|---|---|---|
America/Los_Angeles | PT (PST/PDT) | −8 / −7 |
America/New_York | ET (EST/EDT) | −5 / −4 |
Europe/London | GMT / BST | 0 / +1 |
Europe/Berlin | CET / CEST | +1 / +2 |
Asia/Kolkata | IST | +5:30 |
Asia/Tokyo | JST | +9 |
Abbreviations are ambiguous (IST = India Standard Time or Israel Standard Time?). IANA names are unambiguous and DST-aware. Stick to IANA in code, configs, and calendar invites.
The US and EU shift DST on different dates — the gap between London and New York is "usually 5 hours" but is briefly 4 hours in mid-March and again in late October/early November. The Timezone Converter handles this automatically as long as you’re entering future dates rather than abstract "10 AM PT".
For Americas–Europe overlap: 14:00–16:00 UTC. For Europe–India: 13:00–16:00 UTC. For a true global call (Americas + EMEA + APAC), you almost always have to inconvenience one region — rotate it.
Daylight Saving Time. The US, Europe, and Australia all start/end DST on different dates, so the gap shifts during transitions.
Because abbreviations aren’t standardized. Use IANA names (Asia/Kolkata vs Asia/Jerusalem) in any context where ambiguity matters.
The converter generates a shareable URL that encodes the time — recipients see it in their local zone automatically.