Finding specific date ranges

[Zentrader]

On Sep 6, 7:56 am, kyoso... at gmail.com wrote:
> December 31, 2006    January 13, 2007 # doesn't earn
> January 14, 2007        January 27, 2007 # does earn
> January 28, 2007        February 10, 2007 # doesn't
> February 11, 2007       February 24, 2007 # does

Am I over simplifying if I say that since it appears to be a two week
pay period, the date has to be greater than the 11th unless the first,
or first and second, are on a weekend, in which case it would be > 12
or > 13?  Or a reasonable facsimile thereof, depending on whether or
not the two week period is Saturday through Friday.