Add timestamp to oh-my-zsh robbyrussell theme

According to the zshmisc man page there are several % codes for date and time, eg:

 %D     The date in yy-mm-dd format.
 %T     Current time of day, in 24-hour format.
 %t %@  Current time of day, in 12-hour, am/pm format.
 %*     Current time of day in 24-hour format, with seconds.
 %w     The date in day-dd format.
 %W     The date in mm/dd/yy format.
 %D{strftime-format}

The last one allows codes listed in the strftime(3) man page. Edit your ~/.zshrc file and add at the end a new PROMPT value, eg:

 PROMPT='${ret_status}%{$fg_bold[green]%}%p %{$fg[cyan]%}%c %{$fg_bold[blue]%}$(git_prompt_info)%{$fg_bold[blue]%} %D %T % %{$reset_color%}'

If you want add date/time to the right, you set RPROMPT

local ret_status="%(?:%{$fg_bold[green]%}➜ :%{$fg_bold[red]%}➜ )"
PROMPT='${ret_status} %{$fg[cyan]%}%c%{$reset_color%} $(git_prompt_info)'
RPROMPT="[%D{%y/%m/%f}|%@]"

I added this %D{%m/%f/%y}|%D{%L:%M:%S} to the main theme to display the date and time as mm/dd/yy | hh:mm:ss.

So here is the full command I use:

PROMPT='%D{%m/%f/%y}|%D{%L:%M:%S} ${ret_status}%{$fg_bold[green]%}%p %{$fg[cyan]%}%c %{$fg_bold[blue]%}$(git_prompt_info)%{$fg_bold[blue]%} % %{$reset_color%}${NEWLINE}$ '

Which gives: