Conditional Format On Month Change

I have created a 4 week custom calendar for planning purposes. As part of this I naturally have cells containing the dates of the days involved. These dates have been customised to show only the day as it is more presentable than including the month. The down side to this is it is difficult to identify when the month changes at a glance. Therefore, I would like to do the following:

1. Change the font colour of the day number when the month changes, e.g. December dates in black, January dates in red.

2. In one cell display the months the calendar refers to, e.g. if December and January dates are in the calendar the cell should read December '08 - January '09; if only December dates were included, the cell would read December '08.