How are data quotas calculated?

All NBN Satellite services are calculated within a rolling 28 day window. This can sometimes be confusing as many internet services are based upon a monthly data allocation.

A simpler way to explain this is to ask the question:

Over the past 28 days how much data have I used? Is it less than 24 Gigabytes of upload or less than 150 Gigabytes of both upload and download?

The trick is that you are required to ask this question every day.