When do I take my Birth Control?

I'm on Lutera. I just started this week. I've been really good about taking it everyday at 9pm. 
Yesterday, though, I overslept when taking a nap and ended up taking it at 10:36pm. 
I've heard you only have an hour either way to take it and it still be effective. 
But it's Sunday of spring forward. So do I take it at 9pm, or at 10pm to keep it on schedule? Also, should I be worried about oversleeping and taking it more than an hour later than normal yesterday?