I often find myself needing to append a date (and sometimes a time stamp) to files.
The following will generate the current date in the format YYYYMMDD which is the most suitable for sorting files.
$ date +%Y%m%d
Example output is “20120528” or Year = 2012, Month=05 (May) and day = 28.
Similarly the following will output the current time in the format HH24MMSS (24 hour time)
Example output is “193347” or Hour = 19, Minute = 33 and second = 47 (19:33.47).
The two can be combined:
Example output is 20120528-193347. Note the separation of the date and time with a dash.
You can use these commands in your shell scripts. For example, this will create an empty test file called “Test.txt.20120528-193347”:
$ touch Test.txt.`date +%Y%m%d-%H%M%S`
As you can see, quite handy for organising files.