Convert timestamp
Convert Unix seconds or milliseconds to local and UTC time, or convert a local date/time back to a timestamp.
Conversion
Choose the direction for this conversion.
Enter seconds or milliseconds since 1970-01-01T00:00:00Z. 0 and negative values are valid.
Timestamp unit
Choose explicitly; this tool does not auto-detect units.
Privacy notes
Timestamp and date values are processed in this browser tab. NoNoiseTools does not need to upload the input for this tool.
Avoid pasting sensitive log data if it includes private identifiers, tokens or customer data.
How this Unix timestamp converter works
Timestamp mode treats the entered value as seconds or milliseconds since 1970-01-01T00:00:00Z. Date mode parses the entered date/time as browser-local wall time, then reports the same instant as Unix seconds, milliseconds and ISO.
Seconds vs milliseconds
Many APIs store Unix time in seconds. JavaScript dates usually use milliseconds. Choose the unit explicitly so a 10-digit seconds value is not mistaken for a 13-digit milliseconds value.
Local time vs UTC
UTC is the reference instant. Local time is that same instant displayed using the browser or device time zone. The tool does not detect location or convert arbitrary IANA time zones in this version.
Privacy notes
Timestamps and date values are processed in the browser. NoNoiseTools does not need to upload the input to a server for this tool.
Avoid pasting sensitive log data if it includes private identifiers, tokens or customer data.
What this tool does not include
It does not detect location, query network time, handle leap seconds, schedule events, convert arbitrary time zones or provide legal deadline calculations.
Key terms and assumptionsShort notes about Unix seconds, milliseconds, UTC, browser-local time, date range and no location lookup.
- Unix epoch
- Timestamps are counted from 1970-01-01T00:00:00Z.
- Explicit units
- The tool uses the selected seconds or milliseconds unit and does not auto-detect timestamp length.
- Local date parsing
- Date/time input is interpreted as browser-local wall time.
- UTC output
- UTC and local output show the same instant, not two different timestamps.
- Browser Date range
- Values outside the JavaScript Date range are rejected.
- No location lookup
- Local output uses the browser or device time zone without detecting location.
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FAQs
What is a Unix timestamp?
It is a count from 1970-01-01T00:00:00Z, commonly stored as seconds or milliseconds.
Is my timestamp in seconds or milliseconds?
Many APIs use seconds, while JavaScript often uses milliseconds. This tool lets you choose explicitly.
What does timestamp 0 mean?
It represents 1970-01-01T00:00:00Z.
Why do local time and UTC differ?
UTC is the absolute reference time. Local time is the same instant displayed in the browser's current time zone.
Does this detect my location?
No. It uses the browser or device time zone without a location lookup.
Can it convert other time zones?
Not in this version. Use the Date & Time tools for broader time-zone work.
Does it handle leap seconds?
No. JavaScript Date and common Unix timestamps do not model leap seconds for this use case.