The day before yesterday I was 25. The next year I will be 28. This is true only one day in a year. What day is my Birthday ? Sol: My birthday is on December 31. I am telling this on January 1. Day before yesterday (dec 30) = I am 25 Present day (January 1) = I am 26 this year december 31 = I will be 27. Next year december 31 = I will be 28.