If you go outside at night anytime soon, you’ll notice it’s dark. Also, you might notice a very bright object somewhat low on the horizon, east-west. That would be Sirius, also known as the Dog Star. As Etymonline not so helpfully explains:
“The heliacal rising of Sirius has shifted down the calendar with the precession of the equinoxes; in ancient Egypt c. 3000 B.C.E. it coincided with the summer solstice, which also was the new year and the beginning of the inundation of the Nile. The “dog” association apparently began here (the star’s hieroglyph was a dog), but the reasons for it are now obscure.”
That is, the star that reached its peak during summer when the pyramids were built now does so in midwinter. (This is because global rotation is slowing, so star rises shift relative to earth time.) Interestingly, while mostly referred to by its katakana シリアス in Japanese, its kanji (shared with China) translates as “celestial wolf” (Tenrou, 天狼). Kinda weird how Egyptian hieroglyphs and kanji settled on a common name for this star. ¯_(ツ)_/¯ - William