Float is good.

I just got my credit card bill, and the statement date was the day before they charged my card for the lab equipment. As a result, I can put off paying for that item until approximately January 6 without accruing any interest, giving me plenty of time to get reimbursed before having to pay. It doesn't really matter, but it enables me to keep a bit more cushion in my checking account without having to transfer money from savings.