I am trying to understand when i should book some ET tickets for meetings in europe. I have some meetings booked and some still tentative.

I noticed that fares jumped up a bit at T-1month, does this also happen at T-2weeks or T-1 week etc?
If it does is there a list of which fare codes go at these times?

Of course I understand this can change with loads etc. but any general fare information could be very useful