The Giza plains....the dry season and the rainy season.
How does it work?

Quite simply, as a collector...I buy strategy guides and soundtracks as collectors items, and when it comes to discovering secrets in a game I will flick to the relevant page in the guide. I was doing this during this afternoon as I was trying to do a number of side quests (following the event at Giruvegan). After several attempts at returning to the Giza Plains in order to fight the Gil Snapper mark during the course of the game, it was still the dry season.

I have seen the dry season twice now, and today I found myself able to enter the second rainy season. I defeat the Gil Snapper, and then find I cannot claim my reward until the next damn dry season. Obviously the seasons don't work as you progress in the game, it's a matter of a certain amount of hours...am I right?
I went there once and found it was still the dry season, then half an hour later (after many hours of it beind the dry season beforehand), it then became the rainy season again.

I have checked in the guide, and it does not tell me anywhere (that I can find), how long each season lasts. Does anybody know?