Changes (or rather swaps in and out) the PCs Factions based on the time of day?

I expect so. You'll want to use a script with an http://www.creationkit.com/OnUpdate_-_Form event, I think, in which you would check the return value of http://www.creationkit.com/GetCurrentGameTime_-_Utility and uses http://www.creationkit.com/AddToFaction_-_Actor and http://www.creationkit.com/RemoveFromFaction_-_Actor depending on the result.

Cipscis

Awesome, thank you again sir.

I suppose then this would/might work by just adding the script to the magiceffect of a spell the PC is carrying. So for example if the PC has VampireSunDamage01 there could be a script in the magic effect for SunDamage01 that would check the game time and swap the PCs faction based on the time of game.