In general when looking for the cheapest flight to Paris, try to book your flight during the month of November for the best deal.
In general, most flyers find the cheapest time to book a flight to Paris is about 60 days prior.
From most locations, the cheapest flights to Paris are found on a Tuesday. Booking a Saturday departure is usually the most expensive.
On average you can find the best deals on plane tickets to Paris when looking for flights with evening departure times.