Add multiple attendances for the same day using the API

Hello,

I'm trying to sync the attendances from the project management tool we are using to Personio. That tool records the attendances by project, so sometimes there are more than one attendances for one employee at the same day, i. e.
Project A: 06:00 - 10:30
Project B: 11:00 - 15:00

When I try to add the second attendance I get this error: Existing overlapping attendances periods

Is the any way to add multiple attendances for one employee at the same day by using the API or do I have to do some nasty calculations to add breaks which leads to more nasty data handling when updating the attendances?

Kind regards