DATE & TIME

Unix Timestamp Converter

Convert Unix seconds or milliseconds to a readable date, or turn a date into a timestamp. Every result shows UTC and your device’s local time.

Timestamp → date

Seconds may include up to three decimal places. Milliseconds must be whole numbers. Negative values represent dates before 1970.

Conversion result

Enter a timestamp or date, or load an example.

The exact seconds result retains milliseconds, including negative fractions. Nothing is rounded to whole seconds. Editing inputs clears the previous result.

Batch timestamp conversion

Paste one timestamp per line. All lines use the selected batch unit. Blank lines are skipped; invalid lines get individual errors. Up to 500 lines and 50,000 characters.

Convert a batch to see results and per-line errors.

JSON exports preserve source line numbers and include UTC/local dates or an error for each nonblank line.

Using Unix Timestamp Converter

Read timestamps from logs and APIs, or produce a timestamp for a date. Explicit units and timezone labels keep seconds, milliseconds, UTC and local clock times distinct.

  1. For timestamp → date, enter a decimal value and explicitly choose seconds or milliseconds. For date → timestamp, enter YYYY-MM-DD HH:mm with optional seconds and milliseconds, then choose UTC or device local time.
  2. Click the corresponding Convert button. Current time fills and converts a snapshot from your device clock; examples use a fixed instant. Local times skipped by a clock change are rejected. For a repeated local time, choose the earlier or later occurrence.
  3. Copy exact seconds, milliseconds, UTC ISO text or the local result. Open batch conversion to convert one timestamp per line and copy or download complete JSON results, including per-line errors.

Example

1700000000 seconds = 1700000000000 milliseconds
UTC: 2023-11-14T22:13:20.000Z
Local display depends on your device timezone.

Questions & answers

What is a Unix timestamp?

It measures elapsed time from January 1, 1970 at 00:00:00 UTC. The timestamp represents an instant; timezone labels describe how that instant appears on a local clock.

How do I choose seconds or milliseconds?

Check the format expected by the system that produced or will consume the value. Millisecond timestamps are 1,000 times the corresponding seconds value. This tool requires an explicit choice instead of guessing from digit count.

Are fractional and negative timestamps supported?

Yes. Seconds can include up to three decimal places, such as -0.001 for one millisecond before the epoch. Milliseconds must be whole numbers. Exact seconds output retains the millisecond fraction without rounding.

Which timezone is used for date input?

UTC is the default. You can explicitly choose your device local timezone, shown above the form. Date input does not accept a timezone suffix or offset. Results always include both UTC and local time with the offset at that instant.

What happens around daylight-saving changes?

A skipped local clock time is rejected rather than shifted silently. If a local clock time occurs twice, the tool asks you to choose the earlier or later occurrence. These choices do not affect UTC input. Timezone rules come from the browser and operating system.

What formats and date range are supported?

Use decimal timestamps without exponent notation. Date input uses YYYY-MM-DD HH:mm, optionally with :ss and .SSS, and can use T instead of a space. UTC dates range from year 0001 through 9999. Precision is one millisecond; leap seconds such as 23:59:60 are rejected.

Does current time keep ticking?

No. It captures a snapshot when you click, using your device clock. Click again to get an updated value. An inaccurate device clock will produce an inaccurate snapshot.

Are my dates uploaded, and how does batch conversion work?

Conversion stays in the browser without saving or uploading inputs. Batch mode accepts up to 500 input lines and 50,000 characters, skips blank lines and retains original line numbers. Each nonblank line produces UTC/local results or an error in the complete JSON export.

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