Why should I track my time?

Time tracking is not for invoicing your client

its for knowing how much time you spend doing something and then writing better proposals and having a better overview of how many projects you can and want to work on at a time

If you ask people what time tracking is for, the top answer usually is: So you know how much time to invoice to a client.

In reality it's to know how much time you spend doing a certain task. To write better proposals and to better understand how much work you can take on.

The amount of money you invoice is an arbitrary number that is just based on that time, but will most likely never be that exact number.

With rules its pretty much 80/20: Try to catch 80% of your work with 20% effort on writing rules.