Click "view" next to the staff members' name you want to change the working pattern for. 

Make any changes to the working pattern that have been agreed.  Add these changes as they appear in the contract.

Click the "This member of staff is changing their working hours." field.

Click the "Changes effective from*" field and add the date you have agreed the changes to working pattern will start.

Holiday Manager - How to change the working hours or entitlement for a member of staff