Q. Two questions Re- your answer on simcha begins on the first Adar. When you say that on Adar you increase simcha what does that mean, if you don't have a court case and you anyway say tachanun so where is the simcha reflected?
A. The Talmud (Taanis 29a) mentions; just like when the month of Av arrives, we decrease in joy, so when the month of Adar begins we increase in joy. Shulchan Aruch omits the Adar part of this statement, however Mishna Berura (686: 18) and other Poiskim do mention it. It is also a common minhag and tradition cited in luchos and often posted on signs in shul and at home. Nimukey Orach Chaim (ibid.) and Nittey Gavriel (Purim 11: 3) instruct that each individual should augment his joy by engaging in the activities that bring him happiness. It is known that Rav Chaim Shmuelevitz Zt"l would increase his time of Torah learning during the month of Adar, as this was his way of increasing joy.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a