Another vote for tossing it after a week. Everytime I open something - jarred salsa, pasta sauce, carton of chicken broth - I mark it with a pen as to the date I opened it.
Cartons of chicken broth - as per the carton instructions - are used, frozen, or tossed after 14 days. Same goes for salsa, which has a higher acid content than regular pasta sauce. Pasta sauce or plain tomato sauce goes out after a week.