^You are probably too late to start this year unless you can find a variety that will mature in 90 days or less. Typically the time to start the seeds, assuming you start them outdoors, is after all danger of frost is past for your area. Count back about 120-150 days from the time you want to have fully grown pumpkins, add about a week for germination, and that will give you an approximate date for planting.
"Life is pleasant. Death is peaceful. It's the transition that's troublesome." (Isaac Asimov)