#!/bin/sh

min="$1"
[ "$1" ] && shift
printf "notify-send -u critical %s; bell" "$(/usr/bin/printf '%q ' "${@:-alarm}")" | at now + "${min:-0}" minutes && [ "$min" ] && [ "$min" -ne 0 ] && 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 following codes
#at now + "$1" minutes << EOF && notify-send 'Successfully Scheduled'
#notify-send -u critical "${2:-alarm}"
#bell
#EOF