Do you use the cell phone or wrist watch to know the time?

Hi,

Actually, my question is: when someone asks you about the time, what would you say?
Do you say:
let me look at my cell phone to tell the time,
let me look at my cell phone to know the time,
let me look at my cell phone to check the time, or
let me look at my cell phone to read the time?

Personally I use the cell phone to know the time.

Thanks very much.