Upstack invoices the clients for every 10 day block (2 work weeks) worked by the developer. This is in line with our 2 week trial period, and as the first invoice is issued after 2 weeks (if the trial has been successful) Upstack found it easiest to continue with invoices being sent every 2 weeks.
For example, if your 1st day on the project was a Wednesday, there are 3 work days within your first week (Wednesday, Thursday and Friday).
Therefore making your first 10 day block end on a Wednesday, two weeks later.
This process shall continue, in the same way, until the end of the project.
If you have any questions feel free to contact Robert Dragne - Upstack Client Success Manager - email@example.com.