What is a timestamp in Linux?

While reading about Linux I got the following:

touch provides several options, but here is one of interest:

The -t option allows you to set the date and time stamp of the file. To set the time stamp to a specific time:

$ touch -t 03201600 myfile

This sets the file, myfile's, time stamp to 4 p.m., March 20th (03 20 1600).

Here, I am not getting the logic behind 03201600 --> 4pm, March 20th.

Solution 1:

Welcome to Linux! You probably read that touch text you quoted in your question from a guide or a book.

In Linux, almost every command has a "manual" that explains its options. You can view the manual page of any command by executing man <command> on a Linux machine.

So, from the command man touch:

   -t STAMP
          use [[CC]YY]MMDDhhmm[.ss] instead of current time

So, your example:

-t 03201600

#Breaking it down:

-t    03     20     16      00
-t    MM     DD     hh      mm
-t   month   day   hours  minutes

So March 20th, 4pm (24-hour format).

If you don't have access to a Linux machine, you can view these man pages online from here: http://unixhelp.ed.ac.uk/CGI/man-cgi. The man page for the command touch is found here: http://unixhelp.ed.ac.uk/CGI/man-cgi?touch

Solution 2:

The output you posted explains the format by breaking apart the numbers as (03 20 1600):

03 - March
20 - 20th
1600 - 4:00 PM (24-hour clock, where 0000 is midnight)

Solution 3:

According to man touch:

   -t STAMP
          use [[CC]YY]MMDDhhmm[.ss] instead of current time

So, your timestamp can be translated to DD/MM hh:mm: 20/03 16:00.