When's your first frost date? Generally if you can pull off 55 - 60 days between pollination and first frost it'll be enough time to mature the fruit

I Think Planates's numbers are correct. Then it depend on the variety of gourds too. Birdhouse/ bottle gourds might need longer time to mature than the smaller ornamental ones/

I'm in Texas and our first frost is usually mid November. I have found my plants can sustain a light frost. The plants gets damaged but the fruits can take a little more abuse. So I think you have more than enough time. At least 3 months by my calculation as of 8/1/13.