Time & Date Converters

Switch time zones, convert Unix timestamps, calculate date differences, and check exact age in seconds. Pick a tool and get instant results.

Convert time zones, Unix timestamps, and calculate date differences.

Time is the one measurement that changes depending on where you are standing, and the rules are not tidy. Offsets are not all whole hours, they move twice a year in most of the world on dates that differ by country, and governments change them at short notice. Doing the arithmetic by hand is how a call gets booked for an hour that does not exist. These converters read the same time zone rules your device already carries, so an answer here matches the clock on the wall in the place you asked about.

What this page gives you

• A world clock you can plan against — every place you care about on one timeline, with working hours, weekends and clock changes shaded
• Time zone conversion — second-accurate, IANA-based and daylight-saving aware, for 418 zones
• Timestamp conversion — Unix seconds through nanoseconds, plus Excel serials, .NET ticks and Windows FILETIME
• Date calculation — add or subtract time from a date, or measure the gap between two dates
• Age calculation — exact age from a birth date, including the 29 February case
• Live results — everything recalculates as you type, and the clock ticks while you watch it

The workbench above does all five jobs in one place. Each also has its own page, which is usually what you want if you only ever do one of them or if you are linking somebody straight to the answer.

Current time in major cities

Each city also has its own live clock page, with its IANA zone, its daylight-saving rule and one-click conversions to the other zones.

• Amsterdam
• Auckland
• Bangkok
• Berlin
• Cairo
• Cape Town
• Chicago
• Coordinated Universal Time
• Denver
• Dubai
• Hong Kong
• Istanbul
• Jakarta
• Lagos
• London
• Los Angeles
• Madrid
• Melbourne
• Mexico City
• Moscow
• Mumbai
• New York
• Paris
• Perth
• Phoenix
• Rome
• São Paulo
• Seoul
• Shanghai
• Singapore
• Sydney
• Tokyo
• Toronto
• Vancouver

A time zone is not an offset. It is a rule that says which offset applies at which instant, and the rule changes — sometimes on a schedule, sometimes because a parliament voted last month. The converter reads those rules rather than storing a number per city, which is why a conversion for a date next March uses next March's offset and not today's.

Times that do not exist, and times that happen twice

When clocks spring forward, an hour of wall-clock time is skipped: in New York on 8 March 2026 the clock goes straight from 01:59:59 to 03:00:00, so 02:30 that morning never happens. When they fall back, an hour repeats: 01:30 on 1 November 2026 occurs twice, once at 05:30 UTC and once at 06:30 UTC. Almost every converter silently picks one and shows you a confident answer. This one tells you which case you are in, and lets you choose whether an ambiguous time means the earlier or the later instant, or whether it should refuse and ask.

Offsets that are not whole hours

India runs at UTC+05:30, Nepal at UTC+05:45, and the Chatham Islands at UTC+12:45 — rising to +13:45 in their summer. Australia's Lord Howe Island shifts by thirty minutes rather than an hour when its clocks change. Kiritimati is at UTC+14, so it is already tomorrow there for two hours of every day. The timeline is drawn in half-hour tiles for exactly this reason: an hourly grid cannot line those places up against anywhere else.

A timestamp is a count of some unit since some agreed zero. The Unix epoch — 1 January 1970 — is the common one, but it is not the only one you will meet, and mixing them up produces dates that are wrong by centuries rather than by hours.

Seconds, milliseconds, microseconds and nanoseconds

The same instant is 1704067200 in seconds, 1704067200000 in milliseconds, and 1704067200000000000 in nanoseconds. Left to guess, this converter reads the unit from the number of digits and says which one it chose; you can also state it outright. Nanosecond values are kept exact rather than being pushed through a plain number, which would quietly lose up to 256 nanoseconds on any timestamp after 2001.

Excel serials, .NET ticks and Windows FILETIME

Excel counts days since 30 December 1899 — except that it also believes 1900 was a leap year, so serial 60 is a 29 February that never existed and every serial after it is offset by a day. The usual workaround, subtracting one everywhere, is wrong for the other 125 years. .NET ticks are 100-nanosecond intervals since the year 1, Windows FILETIME uses the same tick from 1601, and Chrome's internal timestamps are microseconds from 1601. All four are supported, and the Excel bug is handled by telling you about serial 60 rather than pretending it is a date.

Adding a month to a date is not adding thirty days, and the difference between two dates is not the gap divided by 86,400,000. Calendar units and elapsed time are different kinds of quantity, and a calculator that treats them the same gives answers that are plausible and wrong.

Month ends and leap years

31 January plus one month is 28 February — or 29 February in a leap year — because that is what a calendar does and what every spreadsheet does. Naive arithmetic rolls the overflow forward and produces 3 March. If you would rather be told than clamped, the panel has a setting for that. Adding a day across a spring-forward keeps the wall-clock time and takes 23 hours of real time; adding 24 hours takes 24 hours and lands an hour later on the clock. Both are correct answers to different questions, and both are available.

Two kinds of total

“How many days” has two answers and conflating them is a real source of off-by-one errors. Elapsed days are complete 24-hour spans, which is what a stopwatch measures. Calendar days are the number of date boundaries crossed, which is what somebody counting on a wall calendar means. They disagree across every clock change and whenever the two times of day differ, so both are shown, along with a count of weekdays for anyone working in business days.

Four steps, and it all runs on your device, not our servers.

1. Pick a mode

   Choose World clock, Convert, Timestamps, Duration or Age in the settings panel.

2. Add the zones you care about

   Search by city, country or abbreviation — type Mumbai, Japan or PST and pick from the list.

3. Choose a day and a slot

   Set the date, then click any tile on the timeline to pin that moment across every zone at once.

4. Read or export the result

   Copy any single value, copy the whole board, or save it as a calendar invite or CSV.

Use these tools when converting time zones, working with timestamps, calculating dates, calculating age, or coordinating across countries.

Ideal use cases

• International communication — find an hour that is reasonable in every zone before you send the invite
• Development and debugging — turn the timestamps in a log into moments, in bulk, in the zone the incident happened in
• Event planning — calculate a future date that respects month lengths and leap years
• Personal use — exact age, anniversaries, and the gap between two dates
• Business operations — coordinate deadlines across offices whose clocks change on different weekends
• Data cleaning — identify which epoch a column of numbers is in before importing it somewhere permanent

A few things that explain most of the surprises.

Key points

• There are 418 time zone identifiers in the IANA database, not 24 — a zone is a region with a shared history of rule changes, not a slice of longitude
• Unix timestamps count seconds since 1 January 1970, and cross 2,147,483,647 on 19 January 2038, which is where 32-bit signed storage runs out
• Daylight saving start and end dates differ by country, so the gap between two cities can change twice a year and be different for several weeks in between
• Not every offset is a whole hour: +05:30, +05:45, +08:45 and +12:45 are all in current use
• Date arithmetic has to account for leap years, month lengths and clock changes — three separate corrections, not one
• Leap seconds exist but cannot be represented in the time value browsers use, so 23:59:60 is refused here rather than quietly rounded

Guidelines that avoid most of the ways a correct-looking answer turns out to be wrong.

Quality considerations

• Store instants in UTC or as ISO 8601 with an explicit offset, and convert only for display
• Check the daylight saving state on the actual date you are scheduling, not on today
• Say which unit a bare number is in before you share it — seconds and milliseconds look alike and are 1,000 times apart
• For repeating meetings, verify the weeks around each region's clock change; the gap between two cities is not constant
• Write dates as year-month-day when a human will read them across borders, so 03/02 cannot be read two ways
• Double-check anything with a deadline attached against an authoritative clock

When not to use it

• Historical dates before the IANA database has reliable rules — pre-1970 offsets are best-effort and pre-1900 entries are local mean time
• Very far future dates, because governments change daylight saving rules with a few months' notice
• Anything where official or legal time governs — verify with an authoritative source
• Sub-second scientific work that needs leap seconds, which this cannot represent

Free covers everything most people arrive for: all five modes, every input and output format, unlimited single conversions, and copying any result. Two things scale with Pro, and both are about volume and delivery rather than accuracy — nothing about a conversion differs between the plans.

• Places on the timeline — four at once on Free; on Pro, as many as your device will draw
• Rows in a batch — 100 at a time on Free; on Pro, as many as your device will hold
• Calendar invites, CSV and shareable links — Pro. Copying to the clipboard is never gated
• Leap seconds — not representable in the time value browsers use, and refused rather than absorbed, on either plan

No time, date, timestamp or city you enter is uploaded. The time zone rules come from the copy your device already carries for its own clock, so the page needs no network access to answer. Even the shareable link puts the board after the # in the URL, the part browsers never send to a server — so a link you paste into a chat tells the site nothing about where you or your colleagues are.

• All-in-one timezone converter
• UTC to Mumbai
• Age calculator
• Date calculator
• Unix timestamp converter