#!/bin/sh

printf 'notify-send -u critical "%s"; bell' "${2:-alarm}" | at now + "$1" minutes && notify-send "Successfully Scheduled"

# at used to not like string like 'Boiling Water!', don't know why now it works, if see similar issue, use folllowing codes
#at now + "$1" minutes << EOF && notify-send 'Successfully Scheduled'
#notify-send -u critical "${2:-alarm}"
#bell
#EOF