Hello,
There is a related topic to our problem:
We have the same problem with the working time for working students in their non-lecture periods (usually 2-3 months a year): normally they work 20 hours/week, during non-lecture periods 40 hours/week (working as a full-time). The suggestion in respective topic is perfect, in which HR manually changes the work schedule after 2 months of full-time schedule back to 20 hours/week. However, I wonder whether there is a workaround that can automatically switch their work schedule rather than switching it manually after their ending of non-lecture period.
Looking forward to any reply soon =)