Basically the expression I am looking for this validation to perform is:
JobDate >= WeekStartDate AND JobDate <=WeekEndDate

JobDate is what the user enters.

Week periods run from Friday to the following Thursday so WeekStartDate is whatever the date is on any given Friday and WeekEndDate is whatever date is on the following Thursday. So today (5/13/2013) would fall within the week of 5/10/2013 to 5/16/2013. If someone tried to enter 5/1/2013 or 5/18/2013 to this period, they would not be allowed.

Can this extension can do this type of validation?

Hello Andy.

In order to achieve such specific validation you can use
DMXZone Calendar 2 with conditional formatting connected to your database :

Using Dynamic Conditional Date Formatting

Creating Date Range Selector

Regards:Vulcho.

Thanks, Vulcho! I will certainly give it a look.
Andy