The truth? You’ll know exactly one evening before—if you follow a sighting tradition. If you follow calculations, you know months in advance. But the real answer is: you’ll know when your aunt sends that group text.
That text will say: “Eid Mubarak! Confirmed by moon sighting in [city] at [time]. P.S. Bring your appetite.” Or, if she’s dramatic: “Eid is TOMORROW—I just saw the crescent through the smog. Allahu Akbar! (And tell your uncle to stop arguing.)”
So, let’s be honest: we know when Eid is when the tension peaks, the WhatsApp explodes, and you finally hear the Takbir. Until then, keep one eye on the sky and one eye on your fridge. The moon will show up eventually—and so will the food.