Workaround for Time Machine skipping automated backups

.tmfix.sh

#!/bin/bash

# .tmfix.sh - workaround for Time Machine skipping automated backups
# 
# Put this script in: ~/.tmfix.sh
# Fill this with your Time Machine dir:
TMDRIVE="/Volumes/Time Machine/"
# And add something like this to your crontab:
# * * * * * /Users/Nyr/.tmfix.sh > /dev/null 2>&1

# if it's the first time...
if [[ ! -e ~/.lastbackup ]]; then
	touch ~/.lastbackup
	exit
fi

oldenough=$(find ~/.lastbackup -mmin +60)

if [[ ! -z $oldenough ]]; then
	# exit if a backup is currently running
	if [[ -e ~/.doingbackup ]]; then
		exit
	fi
	# exit if time machine drive isn't mounted
	if [[ ! -e $TMDRIVE ]]; then
		exit
	fi
	touch ~/.doingbackup
	tmutil startbackup -b
	touch ~/.lastbackup
	rm ~/.doingbackup
fi