Convert UTC Time to UNIX

What this tool does

This is the reverse of decoding a timestamp. You give it a date and time, and it gives you back the Unix timestamp, the seconds-since-1970 number that systems use to store moments in time. It is what you reach for when a database, an API, or a config file wants a date expressed as an epoch value rather than as ordinary text.

How to use it

1. Date and Time. Pick the date and time using the picker.

Press Calculate and the Unix timestamp appears.

How it works

A Unix timestamp is just a count of seconds from one fixed starting point, midnight UTC on the 1st of January 1970, the epoch. So to turn your date into a timestamp, the tool works out how many seconds lie between the epoch and the moment you chose, and hands you that single integer. A date before 1970 would come out as a negative number, since it is before the starting line, but in practice almost everything you will deal with is after it.

Going from a date to a number

This direction, date into number, is the one you need when you are feeding a system rather than reading from it. A common case is building a database query: to ask for everything recorded after a certain date, you convert that date to a timestamp and compare against the stored epoch values. Another is setting an expiry, like a token or a cached item that should stop being valid at a particular time, where the expiry is stored as a timestamp. In both, you start with a human date and need the machine's number, which is exactly what this produces.

It gives you seconds

The number this returns is in seconds, which is the classic Unix and POSIX scale. Some environments, JavaScript and many browser APIs in particular, work in milliseconds instead, which is the same value multiplied by a thousand. So if the system you are handing this to expects milliseconds, multiply the result by 1000 first. If it expects plain Unix seconds, use the number as it is.

Where it fits

Development work where a date has to become an epoch value. Setting a timestamp for an API parameter, building a query that filters by date, generating an expiry time, or writing a fixed value into a config or a test. It is the encoding half of working with epoch time, paired with the decoding tool that turns a timestamp back into a readable date.

Questions people ask

What is a Unix timestamp?

It is the number of seconds since midnight UTC on 1 January 1970, the epoch. It stores a moment in time as a single integer that is easy to compare and sort.

Is the result in seconds or milliseconds?

Seconds, the standard Unix scale. If your system uses milliseconds, like much of JavaScript does, multiply the result by 1000.

How do I go the other way, from a timestamp to a date?

Use a Unix-time-to-date tool, which takes the number and shows you the readable date and time it represents.

What about dates before 1970?

They produce a negative timestamp, since they fall before the epoch. It is valid but uncommon, as most systems deal with times after 1970.