Unix Timestamp Converter

What is unix timestamp converter?

Unix time is how many systems store dates. Databases, logs, APIs and JWT tokens often show a number such as 1700000000 instead of a date, which is hard for people to read.

This converter detects seconds and milliseconds, shows the time in UTC and in your local time zone, and tells you how long ago or from now it is.

How to use the unix timestamp converter

1. Choose the direction.
2. Paste a timestamp, or pick a date and time.
3. Press Convert and read the result.

How the unix timestamp converter works

A timestamp with 11 or more digits is treated as milliseconds, otherwise as seconds. It is turned into a date and formatted as UTC, local and ISO 8601. For the other direction, the date is divided by 1,000 and rounded down.

Worked example

Common uses of the unix timestamp converter

• Reading timestamps in logs and databases.
• Debugging API responses and token expiry times.
• Setting an expiry time as a number.
• Converting dates for spreadsheets and scripts.
• Checking how old a record is.

Tips and common mistakes

If a timestamp gives a date in 1970, you probably passed seconds where milliseconds were expected, or the reverse.

Always store and send times in UTC and convert to local time only when you show them.

Background: what to know before you rely on it

Unix time began as a simple solution in the early 1970s: count seconds from a fixed starting point, called the epoch. It ignores time zones and daylight saving, which is its strength. Two systems anywhere in the world can agree on the same moment, and a time can be compared or sorted as a plain number. Presentation is separate, so a program turns the number into a local time only for display. JavaScript uses milliseconds rather than seconds, which is a frequent source of off by a thousand errors. In January 2038, systems that still use a signed 32 bit counter will overflow, so modern software uses 64 bit values.

Private, free and fast

This tool runs entirely in your browser. What you type or choose is not uploaded to a server and is not saved after you close the page, which keeps it fast and private. It is free to use as often as you like. See more in all developer tools, or browse the full list of tools.

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