literally it can be translated as резиновое время, but nobody says so, тягомотина is another word for something lasting a long time and boring.

We say it "тянуть резину". It means "drag out" - to do something longer, than it takes time

Hello, I've made some googling, and it doesn't seem like there is any good translation of this expression. "тянуть резину" and "тягомотина" are valid and widely used expressions, but they represent some kind of negative attitude to the situation. The closest phrase I can think of now is "Солдат спит, служба идет". It can be literally translated as "Soldier is asleep, the tiime of (military) service is passing". From my experience as a native speaker I can say that usually, when people use this proverb they mean something like: "Yeah, I can relax now and I don't want to do something, because I don't like it. I'd better just wait until my service/working day/something boring ends'." As far as I can understand, this is not exactly what you are looking for, but this was best I could come up with, and you probably will have to explain "rubber time" directly.

maybe время ожидания