Dosage of Valtrex for cold sore?

My doctor prescribed Valtrex for my cold sores. I got it filled months back and I think I have one coming up and I grabbed the bottle and I'm confused on how to take it. So do I take 2 pills now (12:45am) and then take 2 more pills tomorrow at (12:45pm)?? My bottle has 8 pills so I guess the bottle has enough for 2 separate outbreaks??