I'm currently visiting India, and I'm trying to visit as many Vishnu temples as possible. Unfortunately I'm being stymied in some places, for the following reason. Some time in the December-January timeframe, Vishnu temples in Tamil Nadu have a practice called Thailakappu where they remove all the Alankaram or decorations from the Vishnu statue, and apply herbal oil to the statue to preserve the integrity of the stone. Now the Pancharatra Agamas, which are central scriptures for Vaishnavism, prescribe that Vishnu must not be seen by devotees without his Alankaram. So during the time of Thailakappu, the statue is hidden behind a cloth (although in some cases the face is at least visible).
Now the standard time for Thailakappu is in the 10 day period preceding Vaikuntha Ekadashi, known as Pagal Pathu because of the morning chanting of the Alwars' poems during this period. (That is December 19 - December 29 this year.) But some Vishnu temples don't follow that; they start Thailakappu earlier (during Kartikai Deepam or December 2 this year), or they hold it at a completely different time of year. So my question is, which Vishnu temples do Thailakappu at irregular times, and what is the reason for that?
I'm particularly interested in the practices of the Divya Desams, the 108 sacred places of Vishnu sung about in the Alwars' poems.