OP, this is what I posted in a thread about best prices on SW several months ago.
" I have an idea of a reasonable price from our airport. When I see a price & time I like, I book it. We have 2 trips coming up, 1 in mid December & 1 in early May. I did not like the times or prices with JetBlue, so I waited for SW. I was not able to book as soon as flights were released for December. I know I can usually get flights from $80-130 each way. The price was over 200 by the time I got home that day, so I waited. I kept checking & eventually the flight to Orlando dropped to $86 in mid July so we booked. There were only a few seats at that price & after we booked they went up to $125. If I had not seen it & booked right away, we would have missed that price. The way home was still close to $300 at that point, so I only booked one way. That one finally dropped to $109 last week (about 6 weeks later) & I booked it. There is another flight that day that is $86, but I don't like the time as much. So I booked those flights 5 months & 3.5 months out & I'm very happy with my prices.
For the trip in May, the flights opened last Monday. I was booking my flights on points & paying for my husband's flights. My round trip was about 10500 points. For my husband, the way down was $86 & the return flight was 109. So I booked both of us immediately. So those flights are about 9 months out.
We were also at Disney this past May. I did not book on opening day but panicked in Feb when prices jumped & some WGA fares showed as unavailable. I booked our flight home at 292, even tho I knew that was way too much. But I panicked. That flight eventually went down to $79 about 3 weeks later. So that was in March for a trip in May. Thankfully, SW still gives a credit. So I really learned to know the market price & wait for it.
From my experience so far this year, I have booked with very good prices 2 months ahead, 3.5 months ahead, 5 months ahead & 9 months ahead. There really seems to be no magic date to book on. I really think you have to know what price range you should expect to pay, be consistent with watching for that price & book as soon as you see a price in that range. It is nerve wracking but worth it!"
All that to say, there seems to be no rhyme or reason to the drops. I have gotten price drops on Thursday mornings the last few times (and both were at 9 - 10 am , not 6 am either) even tho you read that prices drop on Tuesdays & middle of the night. That hasn't been my experience. You just have to know a good price & book it when you see it. If you will travel again within a year, keep looking so you can get credits."
Sorry, it's a long post, but it shows that I have gotten great prices at all different times. So no, i don't necessarily but the 50 - 100 day timeframe.