I would think this would be best to take “at the beginning of” your day, which for humans is morning.
It’s odd they are saying it’s possible to be best in the late afternoon.
That’s what I was thinking as well. I still have some. I’m glad I did. I developed shingles while in a remote location and couldn’t get the acyclovir immediately. I began treating with prednisone and benadryl. Finally, after 4 or 5 days I was able to get some acyclovir. The doc that treated me said the combo I took was the only thing, apart from acyclovir, that I could do.