Everyday calculator
Time Zone Converter, Convert Any Time Worldwide with DST
Convert any time between world time zones with automatic daylight saving time adjustments. Covers all 38 UTC offsets including half-hour zones.
How CalcMesh converts between time zones
We convert a time from one zone to another using UTC offsets and Daylight Saving Time rules from the IANA Time Zone Database, the reference most operating systems rely on.
Because DST transition dates change by jurisdiction, we apply the current published rules, which we note in our methodology.
According to the Internet Assigned Numbers Authority, which maintains the global Time Zone Database, there are more than 350 named zones and offsets ranging from UTC−12:00 to UTC+14:00, all of which we support.
Time Zone Guide
Common Time Zones
| Abbreviation | Name | UTC Offset |
|---|---|---|
| EST/EDT | Eastern (US) | UTC-5 / UTC-4 |
| CST/CDT | Central (US) | UTC-6 / UTC-5 |
| MST/MDT | Mountain (US) | UTC-7 / UTC-6 |
| PST/PDT | Pacific (US) | UTC-8 / UTC-7 |
| GMT/BST | UK | UTC+0 / UTC+1 |
| CET/CEST | Central Europe | UTC+1 / UTC+2 |
| IST | India | UTC+5:30 |
| JST | Japan | UTC+9 |
| AEST/AEDT | Australia Eastern | UTC+10 / UTC+11 |
Scheduling Tips
- Always specify the time zone when scheduling across regions.
- Use UTC for international meetings to avoid ambiguity.
- Remember that DST changes happen on different dates in different countries.
- Some regions don't observe DST at all (Arizona, Hawaii, most of Asia/Africa).
Worked example, 09:30 America/New_York → Europe/London
IANA zones with DST rules (labelled meeting math; offsets change with the calendar):
- On 2026-09-05 (US EDT, UK BST): New York is UTC−4, London UTC+1 → London is 5 hours ahead.
- 09:30 EDT → 13:30 UTC → 14:30 BST in London.
- On a mid-winter date after US “fall back” but before UK ends BST windows differ - always pick a calendar date in the tool, not a fixed “EST = GMT−5” rule.
- Arizona (America/Phoenix) stays on MST year-round; a Phoenix↔London winter gap is 7 hours, summer often 8.
After you convert
What to do with the numbers
- Put the IANA zone name (America/New_York) in the invite, not only EST/EDT abbreviations.
- Re-run across the DST boundary week if the series spans March or November.
- For multi-region calls, publish one UTC time and let each attendee convert locally.
- India (Asia/Kolkata, UTC+5:30) has a half-hour offset - do not round to +5.
Methodology & Assumptions
This calendar tool counts civil days and applies stated unit rates to the dates and distances you enter. Time-zone edges follow the browser zone database for your inputs.
How this calendar node runs
Date and rate tools count civil days and apply stated unit rates. Zone edges follow the browser zone database. Published domain formulas
govern the identities; when an agency updates rates or thresholds we refresh defaults
and the page lastmod.
| Input | Default | Source / authority |
|---|---|---|
| All inputs | Domain-typical defaults | Editorial methodology, CalcMesh 2026 |