Well this is not a bug as the designers tagged this items description already :) For me this is a low priority issue. It's a cap after all....

I also got hit by an invisible Zombie. I heard its sounds and my body shook due to the hits I took.

Either this: I agree to having a twenty-something hours long ingame day instead of 24 hours!

Or this: Just make it visible to the players in the server list which time it is on the server.

I have 10+ hrs ingame and yet not seen 1 single sunbeam. I have daytime work and live in CET-Zone.