Here is a way of how you can see a timestamp for executed command when using "history" command in Linux.
You can export HISTTIMEFORMAT variable, with appropriate date formatting.
For example you can use: (update in /etc/bashrc or /etc/profile )
export HISTTIMEFORMAT='%F %H:%M:%S '
In this case the history command will give you an output like this:
[root@amitmaheshwari.in ] # export HISTTIMEFORMAT='%F %H:%M:%S '
[root@amitmaheshwari.in ] # history | head
1 2014-05-13 02:41:45 rpm -qa | less
2 2014-05-13 02:41:45 rpm -qa | grep -i net
3 2014-05-13 02:41:45 ifconfig
4 2014-05-13 02:41:45 ifup eth0
5 2014-05-13 02:41:45 ifconfig
6 2014-05-13 02:41:45 ping 10.0.0.1
7 2014-05-13 02:41:45 ping 10.0.15.8
8 2014-05-13 02:41:45 netstat -antp
9 2014-05-13 02:41:45 hostname
10 2014-05-13 02:41:45 init 0
