For example 1388573100 represents Wed Jan 1 11:45:00 CET 2014.
In the near future there is one date coming up where interesting things might happen. The dooms day is January 19th 2038 at 03:14:08 UTC, where all 32-bit signed integer representations of the unix time will overflow and turn into a negative number. More details about this issue can be found at Wikipedia.
Convert a date to Unix time
To convert Unix time back and forth is quite simple as long as you have the GNU date command available on your computer.
Using the +”%s” format string is the way to display the specified date in Unix time. This shows the current time:
$ date +"%s" 1388573100
If you want to convert a specific date into Unix time, the command should look like this:
$ date -d "2014-01-01 11:44:00" +"%s" 1388573040
Unix time to readable format
The other way around, to convert Unix time back into something readable, is much more unknown and the syntax is somewhat hard to remember. To Convert the above example into it’s readable form run
$ date -d '1970-01-01 UTC 1388573100 seconds' Wed Jan 1 11:45:00 CET 2014