Hey @SteffyHR 

Welcome to the Personio Community, we are thrilled to see you here 🥳. I am happy to support you with your inquiry.

There is no direct way to sync the working schedule of a part time worker to the Absence Calendar I am afraid. Instead a workaround of creating an absence would be needed. I would suggest setting up an absence type for your part time employees, no need for accrual policies to be enabled. For each day the employee is due to be absent, they can then input this themselves and it will show up on the calendar. 

I would suggest allowing the employee to put this absence request through without approval. In order to do that simply create an employee role, but do not add any members to it. Next navigate to Settings > Approvals > Choose the absence type you created. Then for the approval step, please select this absence to be approved by the employee role you just created. Due to the role having no member, the absence approval will go through automatically without any approver needed. 

Lastly as you want employees to be able to view this absence within the Calendar, then I would kindly ask that you read through our guide on how to Configure and Manage Access to the Company Calendar. 

On the same topic we were wondering if a weekly day off can be changed without having to modify their work schedule? For example if an employee has Fridays off on principle but exceptionally takes a Monday instead of a Friday off there is no way of seeing this in the calendar, or is there?

For this you can use the same as above, but please ensure that for the absence that the consider time tracked during absence of this type as overtime is disabled. 

If you have any difficulties in setting this up, please let me know and I will guide further.

Best regards, 

Conor