The HISTTIMEFORMAT environment variable only will format the timestamp if used with the history command, simply setting the HISTTIMEFORMAT environment variable puts the Epoch time in the .bash_history. If you want to use the timestamp in something else, write a script that will convert it. If you need further help, come back.
Thanks for the response. I forgot to add my bash version is 2.05b and the histtimeformat command doesn't work below 3.0. I have a cron job that appends the date and time to the history file for root every hour so I can narrow down trouble shooting. Again thanks
I was going to add that but no need. Excellent self-made solution, you might want to make sure to append a pound sign (#) to the start of that timestamp so as to prevent the timestamp from showing up as a command (i.e. when scrolling through previous commands using the "bang" feature of shells or simple scrolling through previous commands with the up arrow)