The following two examples explain how excluding certain days will affect when your work orders are generated.
If you have a weekly PM scheduled for every Monday and your PM is based on the start date, the PM would generate every Monday unless you have a certain date excluded that falls on a Monday. In that case, the PM would not be generated on that Monday, but would wait until the following Monday to generate.
If you have a weekly PM scheduled for every Monday and your PM is based on the end date, the PM would generate every Monday once the previous work order is completed. If you have a Monday excluded, and the current work order is completed, then the next work order would generate on Tuesday of that week.