Kellogg,

You've probably already discovered how to use conditions in a macro...
if not, while in Macro design, run menu item View > Conditions. This
allows you to execute the action next to a condition only if the
condition is met.
Now, the way to determine the current day of week, is through the use of
function Weekday. So, if you want a different report on, say, Monday,
then you would do something like:

Condition        Action
WeekDay(Date,0) = 1    OpenReport (report A)
WeekDay(Date,0) <> 1    OpenReport (report B)

HTH,
Nikos