What is the Dormition?

It is the falling-asleep of Mary, and translation into life which is celebrated on August 15th. In preparation for this great feast of the Mother of God, we observe a two-week period of fasting from August 1-14.

So why do we fast before Dormition?

I love this analogy: In a close-knit family, news that its matriarch is on her deathbed brings normal life to a halt. Otherwise important things (parties, TV, luxuries, personal desires) become unimportant; life comes to revolve around the dying matriarch. It is the same with the Orthodox family; word that our matriarch is on her deathbed, should have a similar affect on us. We fast, not to get what we want, but to prepare ourselves to receive what God wants to give us. Fasting is intended to bring us to the realization of “the one thing needful.” It is to help us put God first and our own desires second, if not last. It also serves to prepare us to be instruments of God’s will, as with Moses in his flight from Egypt and on Mt. Sinai, as well as our Lord’s fast in the wilderness. Fasting turns us away from ourselves and toward God. It helps us become more like the Theotokos, an obedient servant of God, who heard His word and kept it better than anyone else has or could.

Fasting Rule

Orthodox Christians generally follow the same fast, as prescribed by the Church. From August 1-14th, we fast from meat, dairy, fish with backbones, wine and oil. On Saturdays and Sundays are Wine and Oil Days which means on these days the fast is relaxed to permit wine and oil. Of course, fasting is a spiritual discipline that should be practiced with the oversight and direction of your spiritual father. You should consult your Priest if you have any specific questions about the fasting discipline as it applies to you, and your children.

https://www.asceticlifeofmotherhood.com/blog/dormitionguide