This Sugya focuses on a timely topic uniquely applicable to this year.  As this year is a leap year, the month of Adar is doubled.  The question arises - which is the “real” Adar?   The Gemara discusses this question and brings the opinions of various Tanaim.  Obviously, the final determination was that Purim is celebrated during the second month.  This leads to a second question - is there any significance to the 14^th (and 15^th) of Adar I?   We know that Tachanun is not said and fasting is prohibited - but is there an actual chiyuv of Simcha?  The Rishonim debate this question and the halachic ramifications of their different opinions are discussed in the Shulchan Aruch and its Poskim.

Practical questions that arise: 

• Can one be yotzei the din of Simcha/Seudah on Purim Koton at night? Is it different than the regular Purim, where one must fulfill this obligation during the day?
• Given that this year Purim Koton falls on Friday, is it preferable to have a seudah on Thursday night in order to avoid eating a seudah on Erev Shabbos?
• Is there a “Shushan Purim Koton”?
• What about Mishloach manos on Purim Koton?