I can’t think of any other ‘it’ that is meaningless. ‘It’ normally refers to something in the sentences context. But in that and in the sentence ‘it rains’ there is nothing that ‘it’ could refer to. The sky doesn’t snow, the weather doesn’t snow and neither do the clouds.
It really becomes time that it’s been made clear about that! It’s unbelievable that it took so long for someone to call out that it’s the time the It is referring to!
(Now I wait for some nerd to clear up each reference point because I only wrote that because I had the first two parte in my head when I reset your reply!)