There's no timestamp of each command when we are using 'history ' command to see the command records.
We can add timestamp for each command by following steps:
1. Edit ~/.bashrc or /etc/bashrc
export HISTTIMEFORMAT="%m-%d-%Y %H:%M:%S "
Note: m, d are in lowercase, Y, H, M, S are in uppercase.
There's a blank between 'S' and the last Quote Mark.
2. Save the bashrc file, and use 'source ' command to reload the bashrc config file.
3. Done.