Timestamp Converter

Convert between timestamps and dates in every common representation — and see how the input was interpreted.

ConvertersRuns in your browserFree, no sign-up

Options

Numeric input is in

10 digits is almost always seconds, 13 is milliseconds.

Timestamp or date

All representations

Output appears here as you type.

Ctrl + Enter to run

About the Timestamp Converter

Converts between Unix timestamps and readable dates in both directions, showing UTC and your local zone side by side. A timestamp is an absolute instant with no zone attached, so displaying one always means choosing a zone — and most 'off by a few hours' bugs are exactly that choice made twice, differently.

Check the digit count when a date lands in 1970 or the far future. A current timestamp is 10 digits in seconds and 13 in milliseconds, and mixing the two is the single most common cause of a nonsense date.

Frequently asked questions

How does it know whether my number is seconds or milliseconds?

By digit count, and it always tells you which it chose. A 10-digit value is seconds (covering years 2001–2286) and a 13-digit value is milliseconds. Guessing wrong is not a subtle error — it puts the answer in 1970 or the year 55000 — so the interpretation is reported rather than applied silently, and you can override it.

What is the ISO week number?

The ISO 8601 week, which is not the same as "the nth week of the year". ISO weeks start on Monday, and week 1 is the week containing the first Thursday of January — so 1 January can fall in week 52 of the previous year. Financial and manufacturing systems use it, and it is a common off-by-one source in reporting code.

Which timezone is used?

Both. UTC is shown because it is unambiguous, and your browser's local timezone is shown alongside it with the zone name so you can see the offset being applied. Unix timestamps themselves have no timezone — they are always seconds since the UTC epoch.

About the Timestamp Converter

Frequently asked questions

How does it know whether my number is seconds or milliseconds?

What is the ISO week number?

Which timezone is used?