The musical Rent suggests measuring a year in seasons of love, which doesn’t seem particularly easy to quantify. World of Warcraft, meanwhile, measures a year in seasons of item level increases, which can very easily be quantified with some good old-fashioned math. Today is the start of the third season of rewards for Battle for Azeroth, for example, which means that all your loot will get another chunk of levels added on from content and World Quest rewards can scale up higher.
Dungeons will now award level 370 gear at max level, while Heroics drop 385, Mythics drop 400, and the new Mythic-only Mechagon drops 415 gear. Keystone scaling has appropriately increased as well, and the only thing really left out are older raids which now go unloved from their status as being important just a few scant months ago. Shed a tear for Uldir, perhaps, but make sure you know exactly how reward levels are changing today.