Halocho #66 - Why are we happy in Adar?

One increases joy when Adar begins because Adar and (next month) Nissan historically have been full of miracles, including the redemption from Egypt and (nearly a millennium later) the miracle of Purim. Boys and girls born this week will become Bar/Bat Mitzva three weeks before their friends born last week, since 2020 and 2021 have only a single Adar. As we learnt in Halocho #41, girls born 12 years ago during Adar will become Bat Mitzva this month; Adar-2. Since 13 years ago was also a leap year, boys born 13 years ago become Bar Mitzva this year during whichever Adar they were born in. Source: KSA: 141:1, 15:2