Many faucets pay out over weekends, so the transactions will be slightly higher during these periods. I guess many businesses also pay salaries on Fridays and this will also have
a influence. I know I use Bitcoin a bit more over weekends, when I go to the pub with friends, and we all pay for the drinks and snacks in Bitcoin.
I have not seen a difference, because I pay a slightly higher miners fee than the default and that seems to bump my confirmations a little. You have to pay for speed.