Not in general. These things work by supply and demand and the carriers spend a lot of resources trying to track demand and bookings and set prices accordingly. When I'm going on holiday I tweak around if different options of dates and times to work out where the cheaper flights are. As a very generalisation, Americans get so little holiday, they tend to use it to tack onto existing public holidays, so travel around such dates can be more difficult (Christmas, Easter, Memorial Day, Independence Day, Labour Day, Thankgiving etc.).