It depends on your route and the restrictions of any fare sales that may be in place at the time. If you post your route and your proposed travel dates, someone may be able to offer you more help.
some fare structures require a tues/wed/thurs travel in either direction while other fares let you travel on any day of the week. some fares also have a restriction on the time of day flown. like late night travel or early morning only. it all depends on the market.