>>104295149>>104294781Basically what this guy said about 9 months from a few weeks before the winter solstice in the Roku episodes (I guess early the equivalent of December) through to the end of summer (equivalent to mid to late September) with Book Three probably only starting a few weeks before the comet came.
Aang, Katara and Sokka started out 12, 14, and 16 respectively so they probably ended 13, 15, and 17