I'll tell you down to the minute when to get the cheapest fare if you'll give me the next set of winning power ball numbers. Deal?
Bottom line, even before covid, there was no definitive time, no matter what anyone would say. The day of the week, the time of day, the originating airport and the destination airport are all factors on what happens, as is the airline. So someone could say "I always find the cheapest fares 3 months out", but unless you're flying from their city to the same destination and on the same airline, it really doesn't mean anything.
AND, unless someone looks at tickets daily, if not multiple times a day from the day they were released until the day of the flight, they don't know that they got the cheapest price.
We were flying to Europe in April of 2017. I started looking at flights in October. They were routinely $1200-$1800pp. By checking daily (and utilizing google flights), I caught a sale where the tickets were $650pp. The sale lasted 36 hours.