I seem to have missed a fare this week - a trip I'm considering next month doubled in value (on CO's site) from yesterday to day. We're just over 30 days from the outbound flight, which made me wonder:

Are there reliable rules for knowing if a fare went away and is coming back or if you've just missed it (barring a published fare sale)? That is, are there deadlines after which a fare is likely to go up - 30 days, 2 weeks, whatever?

Sorry to clog the thread - but hopefully an answer would be helpful for us relatively novice FTers.