World Clock
View current time in multiple cities and timezones. Compare time zones, find time difference. Free world clock with daylight saving support
"What time is it in Tokyo when it's 3pm in San Francisco" is the easy question. The hard ones: when does Tokyo's time switch from "yesterday relative to SF" to "today" to "tomorrow"? Why does the answer change in March and November even though Japan does not observe DST? What time should you schedule a meeting that works for engineering in Krakow, sales in São Paulo, and clients in Sydney? This world clock handles 600+ named locations, shows current time and UTC offset, and computes overlapping work-hour windows for global meeting planning.
How time zones actually work
A time zone is a region that observes the same UTC offset. The number of zones is ~40 (most named "UTC+X" or "UTC-X"); some have half-hour or 45-minute offsets (India UTC+5:30, Newfoundland UTC-3:30, Nepal UTC+5:45). Locations switch zones over history — Russia eliminated daylight saving and shifted offsets multiple times in the 2010s; Lord Howe Island uses UTC+10:30 winter / UTC+11 summer.
The IANA Time Zone Database (tzdb, formerly "Olson database") tracks every named location's historical and current rules. "Europe/Warsaw", "America/New_York", "Australia/Sydney" — these are the canonical identifiers. Application code should always use IANA names, never offset strings like "GMT+2" (which lose DST information and can be ambiguous).
Working example: scheduling a 3-region meeting
Input
Find a 1-hour slot when all three are in working hours (08:00-18:00 local): - Krakow (Europe/Warsaw) - São Paulo (America/Sao_Paulo) - Sydney (Australia/Sydney) Date: 2026-05-14
Output
Time zones on this date: Krakow: UTC+02:00 (CEST, DST active) São Paulo: UTC-03:00 (BRT, no DST) Sydney: UTC+10:00 (AEST, DST not active) Overlap of 08:00–18:00 local in all three: Krakow 09:00 → São Paulo 04:00, Sydney 17:00 (SP out) Krakow 11:00 → São Paulo 06:00, Sydney 19:00 (both out) Unique 1-hour overlap (Krakow 10:00): Krakow: 10:00 (in office) São Paulo: 05:00 (early! before 08:00 window) Sydney: 18:00 (end of work day) No time exists where all three are simultaneously inside 08:00–18:00 local. Closest compromise: Krakow 10:00 / Sydney 18:00 / São Paulo 05:00. Or rotate the inconvenience.
This is the geographic reality: three timezones spread across 13 hours have no common working hours. Common solutions: rotate which region takes the inconvenient slot (a tradition in genuinely-global teams); accept async-first communication; or pick two and async-update the third.
The DST gotchas
- Northern and Southern Hemispheres are offset by 6 months. When Europe / North America are entering DST (March), Australia / Southern South America are leaving it. When Europe is in summer time (CEST, UTC+2), Sydney is on AEST (UTC+10) — total offset Europe-Sydney drops from 9 hours to 8 hours.
- EU DST transitions on the last Sunday of March (forward) and October (backward). US transitions on the second Sunday of March and first Sunday of November — DST starts earlier and ends later in the US than the EU.
- Most of Asia (China, Japan, India, Indonesia) does not observe DST. Australia is split — NSW, Victoria, Tasmania, ACT, SA observe; QLD, NT, WA do not.
- Permanent DST proposals — the US Senate passed "Sunshine Protection Act" in 2022 but it stalled in the House. EU was supposed to abolish DST in 2021 but member states could not agree. Both regions continue to switch.
- Time zone changes — Russia eliminated DST in 2011, kept "permanent summer time" until 2014, then switched to permanent winter time. Mexico abolished DST in most regions in 2022. North Korea changed offset twice in the 2010s. Always trust tzdb, never historical assumptions.
When to reach for this tool
- You are scheduling a meeting across 2+ timezones and want to confirm the local times for each attendee.
- You are tracking a colleague's working hours in another country and want a glance at "is it sensible to message them now".
- You are debugging a timestamp in a database log and need to know "what local time was UTC 2026-04-15 02:30 in Tokyo".
- You are coordinating a launch across regions and want to know when the "first day" starts in your earliest market.
What this tool will not do
- It will not automatically detect attendee timezones. You list the locations; the tool computes. For automatic detection, calendar tools (Google Calendar, Outlook) read each invitee's configured timezone.
- It will not schedule on your calendar. The tool answers "what time is this everywhere"; the booking happens on whatever scheduling tool you use.
- It will not handle dates more than ~5 years in the future with full accuracy. Future DST rules can change; tzdb updates as governments make decisions. For "what time will it be in Sydney on Christmas 2030", the answer assumes current rules persist — usually correct, not guaranteed.
Frequently asked questions
Why is Beijing UTC+8 even though China spans 5 time zone widths geographically?
Political. China standardized to a single zone (China Standard Time, UTC+8) in 1949, replacing five historical zones. In the far west (Xinjiang) the sun rises and sets ~3 hours later by local solar time than in Beijing — locals informally use UTC+6 ("Xinjiang time") for daily life while the government insists on UTC+8.
What is "GMT" and is it the same as "UTC"?
Effectively yes; technically different. GMT is mean solar time at Greenwich; UTC is an atomic-clock-based standard that stays within 0.9 seconds of GMT via leap seconds. For day-to-day purposes, GMT = UTC. The UK observes GMT in winter and BST (UTC+1) in summer.
Why does my UTC time differ from the time on Google?
Almost certainly because Google is showing your local time, not UTC. To see UTC: search "UTC time" or "current UTC". Some tools default to your computer's timezone unless you explicitly request UTC.
How do I store times in a database for events spanning timezones?
Store UTC timestamps + the original timezone identifier (IANA name like "Europe/Warsaw"). Compute local times on display. NEVER store offsets — they lose DST information. NEVER store "2024-01-15 14:00 local" without the zone — you cannot tell what that means without the zone.
What happens to a meeting scheduled at 2:30 AM on a "spring forward" DST date?
In the US (where DST starts at 2 AM), 2:30 AM does not exist on that date — the clock jumps from 1:59 to 3:00. Calendars vary: some shift the meeting to 3:30, some to 1:30, some warn. Avoid scheduling meetings in the 2:00-3:00 AM window on DST transition dates if portability matters.
Why is India 5 hours 30 minutes ahead of UTC?
IST (Indian Standard Time) was set in 1906 at 5:30 offset from Greenwich, splitting the difference between the two major reference meridians passing through India (82.5°E ≈ UTC+5:30 is the central meridian for the country). The half-hour offset stuck.
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Published · Updated · E-Utils editorial team