**Riddle**: The day before yesterday I was 21, and next year I will be 24. When is my birthday?

**Answer**: If today is the first of January and in the event that my birthday is on 31st December, at that point it is conceivable.

Since the day before yesterday that is 30th December, I was 21 years of age. Recently, that is 31st December I got 22.

On the current year’s 31st December I will get 23 and in the following year’s 31st December I will be 24. In thusly it is conceivable.