why does the earth orbit the sun for 1 month

The Earth orbits the sun constantly, continuously, and all the time.  " 24/7/365 "From the sun's point of view, it takes the Earth roughly 365 and 1/4 days to make the complete trip, all the way around one time.  That's the lengthof time that we call "one year".When you talk about orbiting in one month, you're thinking of the moon orbiting the Earth. THAT length of time is about 27.32 days.

The earth orbits around the sun every 365 days