A family of Microsoft relational database management systems designed for ease of use.
Actually I only need 2 colors as long as they're alternating.
Are the dates an unbroken sequence? If so you can use the Mod operator in the conditional formatting expression:
[Appointment Date] Mod 2 = 0
If there are gaps in the sequence however, then you'll need to build a more complex expression which evaluates to True if the difference between the date and the last previous date to it is zero. For this the primary key will need to be brought into play so that the expression does not compare the current date with itself if the dates are the same. The rows would need to be ordered in date then primary key order, so that for rows of the same date the previous row will have a lower primary key value. You can then use the DMax function to get the date which is <=the current date, and the primary key is less than the current key if the dates are the same.