Unix timestamp basics
A Unix timestamp counts time from 00:00:00 UTC on 1 January 1970. It represents one instant, while the displayed date and time depend on the timezone you choose.
This V1 accepts timestamps in seconds and milliseconds. It does not accept microseconds or nanoseconds because browser JavaScript dates represent time at millisecond precision.
Convert timestamps and dates
To convert a timestamp to a date, enter the value, choose its unit or use automatic detection, and select the display timezone. The results include ISO and local date formats.
To convert a date to a timestamp, enter the local date and time and choose the timezone that gives that input meaning. The converter returns both seconds and milliseconds, plus the start and end of that calendar day.
UTC, timezones and daylight saving
UTC has no daylight-saving changes. Named timezones can contain clock changes and historical offset rules. Some local times do not exist when clocks move forward, and some occur twice when clocks move back. The converter handles these cases explicitly instead of silently guessing.
Current time and day boundaries
The current Unix time panel shows the live value in seconds and milliseconds. Date conversion also gives start-of-day and end-of-day timestamps for the selected timezone, which is useful when defining a local calendar-day range.
Frequently asked questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds since 00:00:00 UTC on 1 January 1970. It identifies an instant independently of a display timezone.
Are Unix timestamps in seconds or milliseconds?
Both forms are common. This converter accepts and produces Unix timestamps in seconds and milliseconds.
How do I convert a Unix timestamp to a date?
Enter the timestamp, choose seconds, milliseconds or automatic detection, then select the timezone in which you want to display the date and time.
How do I convert a date to a Unix timestamp?
Enter the local date and time, select its timezone, and the converter returns the corresponding Unix timestamp in seconds and milliseconds.
Does the converter support timezones?
Yes. It displays timestamps and interprets entered dates in UTC, your local timezone or a supported named IANA timezone such as Europe/London.
How are daylight-saving changes handled?
Some local times do not exist when clocks move forward, and some occur twice when clocks move back. The converter identifies these cases and asks you to resolve an overlap instead of silently guessing.
Does it support microseconds or nanoseconds?
No. V1 supports seconds and milliseconds. Higher precision is intentionally rejected because browser JavaScript dates represent time at millisecond precision.
Does conversion happen locally?
Yes. Dates, timestamps and timezone calculations stay in your browser and are not uploaded to UtiliBits.