Is my timestamp in seconds or milliseconds?

Unix time is conventionally seconds, and a ten-digit number is almost certainly seconds. A thirteen-digit number is milliseconds, which is what JavaScript's Date.now() returns. This tool detects both.

Which timezone is the result in?

Both. The converted date is shown in UTC and in your browser's local timezone, because the majority of timestamp bugs come from confusing the two.

What is the Unix epoch?

Midnight UTC on 1 January 1970. A Unix timestamp is the number of seconds elapsed since that instant, ignoring leap seconds.

Time / LOCAL TOOL

Unix Timestamp Converter

Convert Unix timestamps and ISO dates locally in your browser.

Runs locally — input is never uploaded

InputPaste a Unix timestamp or ISO date

ResultReady when you are

WHAT IT DOES

Epoch seconds to a date you can actually read.

Paste a Unix timestamp to get the corresponding date in both UTC and your local timezone, or paste an ISO 8601 date to get the epoch value back. One Convert button does both: a bare number is read as an epoch and anything else as a date, and the result says which it read. Conversion uses your browser's own date implementation, which is the same one your frontend code will use.

Why use it?

Use it to compare timestamps from logs or APIs with human-readable dates and catch seconds-versus-milliseconds or timezone mistakes.

How to use this tool

Enter a numeric epoch or an ISO date with an explicit offset, then convert.
Check the detected unit and compare UTC with the local-time result. For a simple reference, 0 represents 1970-01-01T00:00:00.000Z.
When sharing a time, copy a representation with its timezone or specify the epoch unit; a bare local clock reading is ambiguous.

Details and limitations

Both seconds and milliseconds are recognized; the magnitude of the number decides which, and the result names the reading it used.
Results are shown in UTC and in the browser's local timezone so off-by-one-day mistakes are obvious.
ISO 8601 input with or without an explicit offset is accepted.
Values that are not a valid timestamp or date produce an explicit error.

WORKED EXAMPLES

An explicit timezone removes a date ambiguity

Convert this ISO date with its UTC marker. Compare the UTC result with your local display rather than assuming both clock readings should be identical.

Date

2026-01-01T00:00:00Z

Expected result

1767225600 seconds or 1767225600000 milliseconds since the Unix epoch. The local date may differ from January 1 depending on your timezone; that is the same instant, not a conversion error.

COMMON QUESTIONS

Unix Timestamp questions

Is my timestamp in seconds or milliseconds?: Unix time is conventionally seconds, and a ten-digit number is almost certainly seconds. A thirteen-digit number is milliseconds, which is what JavaScript's Date.now() returns. This tool detects both.
Which timezone is the result in?: Both. The converted date is shown in UTC and in your browser's local timezone, because the majority of timestamp bugs come from confusing the two.
What is the Unix epoch?: Midnight UTC on 1 January 1970. A Unix timestamp is the number of seconds elapsed since that instant, ignoring leap seconds.