Question

I would like to get time before midnight in bash on Mac OS (which has not the same date utility as many Linux distro).

For example, at 23:56:03 I would like to get : “00:03:59”.

Answer 1

OSX Does have the date command

see – OSX Date man page

To get just the time use:

date +"%T"

You need to use some BASIC maths

#!/usr/bin/env bash
hours=`date +"%H"`
minutes=`date +"%M"`
seconds=`date +"%S"`
# Time till midnight
echo `expr 23 - ${hours}`" hours, "`expr 59 - ${minutes}`" minutes, and "`expr 59 - ${seconds}`" seconds "