LinuxConfig -

Many UNIX application are using an EPOCH time to determine a date, on most Linux systems an EPOCH time started on 1.1.1970 and will end on 18.1.2038 as defined by a time_t UNIX C library. Epoch time digit contains a number of seconds since the start of epoch ( 1.1.1970 and 10 hours ).

To get a better understanding consider an example where epoch number is "1". Now convert this epoch time to a real time/ When using bash we can execute a following command:

~$ date --date "Jan 1, 1970 00:00:00 +0000 + 1 seconds"
Thu Jan  1 10:00:01 EST 1970

To get a current epoch time we simply use date command as follows:

~$ date +%s
1284763671

As already mentioned above, to convert a epoch time digit to real time we can use for example by
BASH:

~$ date --date "Jan 1, 1970 00:00:00 +0000 + 1284763671 seconds"
Sat Sep 18 08:47:51 EST 2010

or

date -d@1284763671
Sat Sep 18 08:47:51 EST 2010

PERL:

~$ perl -e 'print scalar(localtime(1284763671)), "\n"'
Sat Sep 18 08:47:51 2010

NOTE:

To convert to Coordinated Universal Time using bash type:

~$ date -ud@1284763671
Fri Sep 17 22:47:51 UTC 2010