Maybe she's thinking that it is going to affect the time u guys can spend together... Tell her that you will not allow anything to come between that... its cheesy but works as long as u actually mean it.

What fenicks said. Just get all romantic with her, tell her she's the most important thing in the world, etc. and it will all go ok. And if push comes to shove, you could just tell your boss, "too much, can wee go back to the 24 hours thing?", and if your boss is reasonable, he won't fire you for asking.

Money comes first, then women. Remember that good sir.
She should be happy, even if she isn't i doubt she'll break up with you over it so your okay.
When it comes down to it, it depends on how far you've gotten with her, me and my buddy both used to do anything for our girlfriends, but after the dirty was done that attitude disappeared.
When in doubt always think "what would Clint Eastwood do"