Hi Mike,
Try Tools > Change Working Time. Select the column heading for Sunday(first
S) click in the option button that says non-default working time. Repeat
for Saturday (the last S).
You can get both Sunday and Saturday with one go if you click on the column
heading for Sunday and then press and hold your control key and click on the
column heading for Saturday.
I hope this helps. Let us know how you get along.
Julie