This spreadsheet is a great tool to use if you know your way around Excel a bit and you have around 5 employees or less.
Any more than that and I recommend you use Bindle.
We built Bindle to specifically manage leave bookings and balances. It is simple, cheap ($1.50 USD per person per month), and does a much better job than any spreadsheet could ever do. Okay, shameless plug over.
If you have any questions, just drop us a line. Who knows, you might become a Bindle customer one day!