Bash History: Display Date And Time For Each Command

How do I display shell command history with date and time under UNIX or Linux operating systems?

If the HISTTIMEFORMAT is set, the time stamp information associated with each history entry is written to the history file, marked with the history comment character. Defining the environment variable as follows:
$ HISTTIMEFORMAT="%d/%m/%y %T "
OR
$ echo 'export HISTTIMEFORMAT="%d/%m/%y %T "' >> ~/.bash_profile
Where,
%d - Day
%m - Month
%y - Year
%T - Time
To see history type
$ history
Sample outputs:

....
..
  986  11/03/10 04:31:36 memcached-tool  10.10.28.22:11211 stats
  987  11/03/10 04:31:36 w
  988  11/03/10 04:31:37 iostat
  989  11/03/10 04:31:37 top
  990  11/03/10 04:31:37 at
  991  11/03/10 04:31:38 atop
  992  11/03/10 04:31:40 collectl
  993  11/03/10 04:31:41 grep CPU /proc/cpuinfo
  994  11/03/10 04:31:45 vmstat 3 100
  995  11/03/10 04:31:55 sar -W -f /var/log/sa/sa12
....
..

References:

For more info type the following commands:
man bash
help history
man 3 strftime