[SOLVED] linux date -- increment current date by minutes but prevent overflow (rollover past midnight)

Issue

So I'm trying to get a date, 1 minute into the future, but not allow midnight rollover, e.g.

date -d "23:58:42 300 seconds" +%H:%M:%S

returns "00:03:42", however I want it to be capped at "23:59:59". Any ideas how?

Solution

300 seconds is not a minute, but, the easiest way would be a simple script:

#!/bin/bash
t="$1"
interval="$2"

h=$(date -d "$t $interval seconds" +%H)
if [ "$h" = "00" ] ; then
    echo "23:59:59"
else
    date -d "$t $interval seconds" +%H:%M:%S
fi

This works well if your interval is under an hour.

Answered By - Ljm Dullaart

Answer Checked By - David Goodson (WPSolving Volunteer)