The best time of the year to paint your home is typically in late spring and early summer when it’s warm outside and moisture is low. This can change based on your geographic location. For example, fall can be a good time to paint in California when the difference between high and low temperatures is low. Your painter will select the optimal time to start your exterior painting project.
Some contractors work on time and material others on a firm contract. I would never hire the former and am leary of the latter. A contractor may low-ball a bid to get the job planning to make a killing on change orders. If you say good morning to them, they charge you extra for that. If the contract is not very, very specific and extensively fleshed out or if they display their change order schedule prominently on top, show them the door.