[devilsgrin]

it seems to me that from Pawn of Prophecy to the end of Seeress of Kell is about 12 years.
We start out with Garion at 14. By Queen of Sorcery he's 15.
In castle of wizardry he turns 16 (as does Ce'Nedra).
From the end of Enchanters End Game to the beginning of Guardians of the West is about 8 years making Garion roughly 24/25. It would stand to reason that the quest across Mallorea would have taken roughly 2 years...the time it took for Geran to become a 2 year old...
So unless my maths are faulty thats roughly 12 years.

Eriond first appears to Zedar as a toddler of about 2. During the events of the Belgariad, he is referred to as appearing around 6. this fits with him being 14-ish once the malloreon adventures begin (him being the focus of this quest and being 14 at the beginning, and Garion being the same when his journeys began - part of the continual repetitions that Garion mentions in Tol Honeth perhaps... or Eddings meddling?).