Rashi quotes the famous Chazal that explains that although Hashem seemingly finished creating the world, the creation wasn't fully stable. Creation was conditional on a key component - Torah which would be given on THE sixth day, the sixth day of Sivan, more than 2000 years later. And, once the Torah was given, creation is dependent on its study. As long as Torah is studied every second of time, the world continues to exist as a result. The Yom HaShishi series is dedicated to those who study the daf every day and their wives and families who support them. With self-sacrifice and dedication, no matter if it's 10 below zero or 104 degrees, no matter if it's raining or snowing or if they're traveling or busy, the Daf must get learned. They learn with candles during hurricanes and little reading lamps of airplanes, busses, and trains. Some wake up at 4:00 AM and some stay up till 2:00 AM. It doesn't matter how, when, or where, they learn The Daf.