How to check which day is good and which is bad for offering fire puja
(jin sek, "offering burning")

Doing Astrology (to determine) where the Sage Fire Deity is Svasti. Whoever wishes to do the offering burning needs to do astrology (to determine in which of) the three levels the fire deity is abiding (i.e. above earth, on the earth, below the earth).

Keep the number of the Tibetan date as a base (with your mala or whatever count from the first day of the Tibetan month up to the day when you wish to do fire puja). Add one also for that day (whether Sunday, Monday, Tuesday, etc.) (It is very important to check the Tibetan calendar from the first day of the month to see whether any days are added or omitted in that month). Add one extra on that (if you are doing with the mala then count one more bead). Then divide by four (counting off just from one side of the mala).

If what extra appears is just one, then the fire deity is abiding in the Realm of Thirty-Three Deities. Therefore if the attainer does offering burning puja it is bad for the life (life obstacle).

If there are two left, the fire deity is abiding below the earth. If you offer burning, the naga gives sicknesses and you lose wealth, there will be famine and so forth.

If there are three or four left, the fire deity is abiding above the earth. If you offer burning puja, the attainer will attain two attainments (common and sublime).

Longdol Lama said:
"Your own infinite pure appearance cannot eliminate others' impure appearance. The river appears to the preta as pus. As it is mentioned in Madhyamika text, the nectar that appears to the devas cannot eliminate others' karmic appearance of water and pus and blood."
Dictated to Ven Sarah at Land of Medicine Buddha prior to the Great Medicine Buddha Burning Offering, November 2001.