Great except a bunch of places are tropical and thus don’t have four seasons as you experience it.

Thailand technically has three and people only really reference one (“winter”)

Also, I know “summer” means you get more leeway on when to actually release but is “mid year” or “late 2019” or “around November” really that hard, especially given that from what I hear, your seasons all start on weird dates?? (In Australia seasons officially start on the first of a given month)

India officially has four seasons, but they are winter, summer, monsoon and post-monsoon (autumn). Depending on the place, the year may also have six seasons of two months each. [1] In general conversations, you may find people talking about summer and winter, with a sprinkling of rainy season, and not much about others.

So any definition that goes by some restricted American version (as pointed out by people living in the U.S. here) of seasons is not really applicable to 90% of the world's population. As you dig deeper into the climate of different countries, states/provinces, regions, etc., you may probably find your 90% figure drop to 10% or less.

[1]: https://en.wikipedia.org/wiki/Climate_of_India#Seasons

Hemispherically true, though if you live near the equator, I don't think you have these kinds of seasons.