Helpers can enter their own time preferences (prefer and dislike times), and you can also allow them to set their own “cannot help” times by changing that option on your SETTINGS>Helper Permissions page.
Coordinators can also enter the time preferences and availability for helpers by editing each helper record.
Note: Time preferences do not generate shifts, they can be used by AutoFill when you auto assign the shifts you have added or imported each week.
Normally the Repeating Weekly preferences would be added first.
Then if those will change on a certain date, from that same page you can set the FUTURE Repeating Weekly prefs.
The Future Repeating Preferences go into effect on the specified date and will continue on until changed. Once the date they go into effect has passed, you can enter a new set of Future Repeating Preferences that will begin on another future date.
Note that “Date Specific Preferences” always override “Repeating Preferences.” So if it seems like your Preferences are not being taken into account when you save, then likely they are being overridden by Date Specific Preferences.
In this case, the new set of Repeating Weekly Preferences will be go into effect on August 30. After that date, they will become the Repeating Weekly and the Future Repeating can be set for another future date.