When you type the command "history" then Linux will return the previously runned commands and prefixes them with digits:
root@dev /root # history 1 command 2 command 2 3 command 3
If you want to see the date and timestamp instead of the enumeration then run:
echo 'export HISTTIMEFORMAT="%d/%m/%y %T "' >> ~/.bash_profile; echo 'export HISTSIZE="INFINITE"' >> ~/.bash_profile; source ~/.bash_profile
Now re-login to the shell and from that moment every command will be recorded including date/timestamp. The next time when you run history it will show:
root@dev /root # history 2019-02-15 19:14:41 command 2019-02-15 19:15:41 command 2 2019-02-15 19:14:41 command 3