What's the difference between duration and billable time?
Duration takes the time from the first person in the Space to the last person in the Space. Billable time is only counted when two or more people are in a Space simultaneously.
Usage is calculated per second at any time where there are two or more connections to a Space. If there are two connections to a space, and one drops out and rejoins, the time where there was 1 connection will not be billed for.
This also means that your teachers can join a Space to prepare for a lesson for as long as they like and you won't be billed for the time they spend alone in a Space.
For more Pricing FAQ visit our Pricing FAQ page.