I would like to ask you a question about the written format of time, which one is right, 4.30 or 4:30? Should a dot or a colon be used?
As with so many things, this is a matter of style, and style will change depending on where you are and who your audience is.
In the US, it's 4:30.
Apparently, in the UK, it's 4.30.
The latter would look wrong to me. I guess my version would look wrong to Rover.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.