Around end of November you get 5000 DMMpt for ticket deal.
It's provide an 11 roll + 1 ticket that can trade for gold and / or rainbow girl.
Early in December you get 5000 DMMpt gacha.
It's provide an 11 roll with guarantee random 1 rainbow that you don't own.
It come along side with useless rainbow and gold elixir.
At the end of december you get another 5000 DMMpt deal.
Roll it to obtain speacial seal stone that can trade for any gold girl you want.
And you will also get 1 rainbow slot.
On New year day you get a short time special deal. (Deal available only for 4 days)
A 3000 DMMpt for 11 roll that guarantee 2 girls will be 5* or higher. (Can get dupe)
Bonus with 15 gems, 1 pink blossom heart and some kind of medal that I don't what is it.
A 5000 DMMpt for 11 roll that guarantee 3 girls will be 5* or higher. (Can get dupe)
Bonus with 30 gems, 1 gold skill and 1 gold slot.
A 10000 DMMpt for 11 roll that guarantee random 1 rainbow that you don't own.
Bonus with 75 gems, 1 rainbow skill and 1 rainbow slot.
I don't found anything about cheap deal during Christmas.
So if anyone have data about it please share.