Why does another site show a value 8 hours off?

The timestamp itself has no time zone. The mapped date depends on the zone the other tool assumed — the raw number is usually the same.

Why is the converted date close to 1970?

Seconds may have been interpreted as milliseconds, reducing the interval by a factor of 1000. Reading milliseconds as seconds produces a distant future date. Check the unit.

What happens at DST boundaries?

A skipped local time is rejected. A repeated autumn hour is ambiguous; use ISO 8601 with an explicit offset to select the intended instant.

Can I go before 1970?

Yes. Use a negative number of seconds; the date side will show correctly.

Can automatic unit detection handle every date?

No. Both 1000 milliseconds and 1000 seconds are valid values. Choose the unit from the producing system's specification, rather than relying only on the number of digits.

Does changing the time zone change a timestamp?

No. A timestamp identifies the same instant. The zone changes its displayed local date and determines how an offset-free date is interpreted when converting back.

Unix timestamp converter

Convert between timestamps and dates in a chosen time zone

Computed in your browser

Choose seconds or milliseconds and a time zone, then convert in either direction. Check the resulting date when using automatic unit detection.

Input — timestamp

Time zone

Timestamp unit

Input — date time YYYY-MM-DD HH:MM:SS · ISO 8601 (2026-01-01T12:34:56+08:00)

Browser clock

Output

–

Example

Input

1735689600

Example result

UTC: 2025-01-01 00:00:00
Asia/Shanghai: 2025-01-01 08:00:00

Select seconds. Both displayed dates refer to the same instant.

Technical details & limits

Unix time uses the UTC epoch of 1970-01-01; zones affect the displayed wall time. Automatic unit detection is a digit-length heuristic: select seconds or milliseconds explicitly for early or distant dates. Offset-free dates use the selected zone. During a DST overlap, include an explicit UTC offset to identify the intended instant.

About this tool

Convert Unix seconds or milliseconds to a date in a selected time zone, or convert a date back to seconds. Check API fields, logs and database values, including negative timestamps and ISO 8601 dates with offsets.

Use cases

Figure out which local time a timestamp returned by an API actually maps to.
You see a large number in a log or a database — is it seconds or milliseconds?
Translate a human-entered date into the timestamp you will store in the database.
Line up trigger times across time zones for a scheduled job or shift roster.

How to use

Type seconds or milliseconds into the timestamp box — the tool auto-detects by length.
Type YYYY-MM-DD HH:MM:SS or an ISO 8601 string (offset optional) into the date box.
Pick a time zone. Conversion runs in both directions with the buttons.
Click “Example: now” to fill both fields with the current browser time.

Input & output

Input: A number (10-digit seconds or 13-digit milliseconds) or a date string (with optional time-zone offset).
Output: A date string in the chosen zone, or a seconds-precision Unix timestamp.
Limits: No leap-second compensation. If your ISO string already carries an offset, the tool respects it and does not re-apply the selected zone.

Notes

Automatic detection is a heuristic. Select the unit explicitly when precision matters and include an offset for repeated DST times.

FAQ

Why does another site show a value 8 hours off?: The timestamp itself has no time zone. The mapped date depends on the zone the other tool assumed — the raw number is usually the same.
Why is the converted date close to 1970?: Seconds may have been interpreted as milliseconds, reducing the interval by a factor of 1000. Reading milliseconds as seconds produces a distant future date. Check the unit.
What happens at DST boundaries?: A skipped local time is rejected. A repeated autumn hour is ambiguous; use ISO 8601 with an explicit offset to select the intended instant.
Can I go before 1970?: Yes. Use a negative number of seconds; the date side will show correctly.
Can automatic unit detection handle every date?: No. Both 1000 milliseconds and 1000 seconds are valid values. Choose the unit from the producing system's specification, rather than relying only on the number of digits.
Does changing the time zone change a timestamp?: No. A timestamp identifies the same instant. The zone changes its displayed local date and determines how an offset-free date is interpreted when converting back.

Related tools

Unix timestamp converter · Convert between timestamps and dates in a chosen time zone — Unix timestamp converter — Tool illustration · dayeku.com