As well as Dallas did, and as many viewers as it had, I have to think that it would have had even more viewers if it had been aired on any night from Sunday through Thursday night. Friday night has a special place in our society. Most people finish their work week at 5 or 5:30 PM on Fridays and they like to go out that night to celebrate. The only night when people are even more likely to go out for entertainment is Saturday night. Also Dallas, unlike Murder She wrote or 60 Minutes, had a lot of viewers in the age range which is most likely to go out on Friday nights. There were some seasons where Dynasty barely edged out Dallas for the number one spot, but Dynasty had the huge advantage of being aired on a night when most people had work or school the next day, so they were more likely to be home then they would have been on a Friday night. Suppose Dallas and Dynasty had switched time slots. Do you think Dynasty would have ever beaten Dallas in the ratings if that had been the case? I seriously doubt it. Dynasty never won that number one spot by a good sized margin; it was always close. Usually Dallas beat Dynasty for that spot in spite of airing on Friday nights. Dallas was so good that many people waited until it was over (10 PM Eastern Standard Time) to leave their homes for the night clubs or wherever they where going to go for that night's entertainment. I doubt so many people would have done the same for Dynasty if it had been the show that aired on Friday nights. As many viewers as Dallas had, it's hard to make any convincing case for it to have not gotten even more viewers if it had aired on a night from Sunday through Thursday night. That Dallas had the number of viewers it did and for it to have won the number one spot as many times as it did despite airing on Friday nights is a testament to just how good of a show Dallas was and just how big of a place it had in the hearts of people.