Red Jenny Attends A Party

hmm..you didn't say, but I am guessing Xbox360...

And if that is true or any other console, check your console date and time settings...the war table missions base their completions off of real time and they use the consoles time clock to do this.  So if something resets or alters the system time clock, then it effects the time left in quest, and most times this is due to the xbox360 losing track of time when shut down, as it gets older.