Spending hours in the sun ?

Hi, I plan on returning to cycling soon and I was wondering if anyone has been able to spend hours in the sun on this stuff. I was hoping that as long as I reapply my sunscreen as advised, I can ride for 4 + hours in the summer without my face getting sunburnt.

I would only be riding for 4+ hours once a week really, the rest of my rides would be anywhere from 1 - 2 hours long.

Edit : These comments are all reassuring, thanks.