Developer tool · Dates & timezones
Turn any timestamp into every timezone at once
Paste Unix seconds, milliseconds, microseconds or nanoseconds — or an ISO 8601 string, or plain words like “1 March 2026 14:30”. See UTC, ISO 8601, RFC 2822 and the local time in any city, with offsets, weekday, ISO week number and how far away it is.
1 · Paste a time
timestamp, ISO or wordsProcessed on your device with the browser's own timezone database. Input is never uploaded or saved.
2 · Choose timezones
3 · Local time → timestamp
the reverse directionThe same moment, everywhere
| Timezone | Local date & time | Offset | Abbr. | Weekday | ISO week | Copy |
|---|
Every common format
click to copyHow to use Timezone Converter
Everything below runs in this tab. Nothing is uploaded, and no account is needed.
Step by step
- Paste a timestamp, an ISO 8601 string or a readable date into Paste a time. Digits are read as Unix time; the unit is detected from the length and can be forced.
- Pick the timezones you care about in Choose timezones — add or remove cities, and your own local zone is always included.
- Read The same moment, everywhere for local time, offset and weekday, and Every common format for copy-ready strings.
- Need the reverse? Use Local time → timestamp to type a wall-clock time in a chosen zone and get the Unix value back.
- Copy a single row, copy every row, or download the table as CSV. Nothing leaves this tab.
Details and limits
Which unit is it?
Unix time counts seconds from 1970-01-01T00:00:00Z. Ten digits usually means seconds, thirteen milliseconds, sixteen microseconds and nineteen nanoseconds. The detector uses that length as a hint only — force the unit in the dropdown when it matters, because a value near a rounding boundary can be wrong.
An offset beats an assumption
A timestamp is absolute, so it needs no timezone. A written date without an offset is ambiguous: “2026-03-01 14:30” is a different instant in Istanbul and in Los Angeles. This tool shows which zone it assumed and lets you change it.
Leap seconds and range limits
Unix time has no leap seconds: 23:59:60 cannot be represented. Values are held as BigInt internally, and anything outside the JavaScript date range (about ±8.64 × 10¹⁵ milliseconds, i.e. years −271,821 to 275,760) is reported instead of silently wrapped.
Offsets change with the seasons
Offsets and abbreviations are computed live from your browser's timezone database, so daylight-saving transitions are already reflected. Two zones can share an abbreviation while being hours apart — the ±HH:MM offset is the reliable part.
Read the worked guide on Unix timestamps · Simple seconds or milliseconds converter · Install for offline use
Frequently asked questions
How do I convert a Unix timestamp to a readable date?
Paste the number into Paste a time. The tool detects whether it is seconds, milliseconds, microseconds or nanoseconds, then shows the matching date and time in UTC and in every timezone you selected. Copy the ISO 8601 or RFC 2822 line if that is the format you need.
What is the difference between Unix time and ISO 8601?
Unix time is a single number of seconds since 1970-01-01T00:00:00Z, with no timezone attached. ISO 8601 is a text form such as 2026-03-01T11:30:00Z that names the calendar date, the clock time and the offset. Both describe the same instant; ISO 8601 is readable by people, Unix time is convenient for arithmetic.
How do I know whether a timestamp is seconds or milliseconds?
Count the digits: a current timestamp in seconds has ten digits (for example 1791676800), in milliseconds thirteen (1791676800000). The detector uses the digit count, and the dropdown lets you override it — always override it when the value came from an unfamiliar API.
Does it handle daylight saving time?
Yes. Every zone's offset is computed from your browser's timezone database at the exact instant you entered, so summer and winter offsets are both correct, including the twice-a-year switch. Converting a wall-clock time picks the offset that applies to that local time.
Can I convert a date in one timezone to another timezone?
Use Local time → timestamp: choose the date, the clock time and the zone the time is written in, and the tool returns the Unix value plus the same instant in every other zone you have selected.
Is my timestamp uploaded anywhere?
No. Parsing, conversion and formatting all happen in this tab with the browser's own Intl APIs. Nothing is sent to a server, nothing is stored, and closing the tab discards the input.