I mean people still wanna play but I'm guessing everyone doesn't join cuz they dont see anyone online. If you got about 4-5 players on then players will start joining and it usually lasts for the rest of the day. If you ask someone on discord or forums then I'm sure they'll be happy to join. If you're talking about UK time then I'd say about 5-6pm because that's when most people are back from work and school