RSet improperly parsing
When making a patch request to update the end date of a schedule, the end date is not set properly. Instead of being set to the specified UNTIL date, it appears to be set to the DSTART plus the duration, as editing the request only changed the database's end date once the DSTART changed. After checking the RSet several times in many ways, I have concluded that the RSet is not the sorce of the problem.
To upload designs, you'll need to enable LFS. More information