Don't bother.
As I understand it, what you are trying to do is done for you when the programme is compiled.
It is a tempting avenue, particularly as you are probably around 35k at the moment and looking to snatch victory from the jaws of defeat with a little judicious shaving. Besides, your SD card suggests you may want to add an on-board clock later, which will only make the situation worse.
$25 will see you with a Mega and all your problems are solved.