Daily work schedule variant

We have the following scenario:

Employee normally works Monday thru Thursday 10 hours OR Tuesday thru Friday.

On a week in which there is a holiday, the employee's schedule changes to 8 Hours Monday thru Friday.

I created a daily work schedule variant to change the holiday to 8 hours, however how would I go about changing either the days preceding or following the holiday to 8 hours.

Thanks in advance,