盆と正月が一緒に来たよう
Meanings
1
as if two great things happened at once; as if Christmas and one's birthday came together
Idiomatic expression describing a situation where two very happy or fortunate events occur simultaneously, like the two busiest or most joyful times of the year coinciding. Often used with 忙しい or 嬉しい. The literal image is the Bon Festival and New Year arriving together.
Today is payday and also my girlfriend's birthday. It's as if Christmas and my birthday came at once.
With the new product launch and the financial closing overlapping, it's as busy as if the two busiest days of the year came together.