like i said earlier, i dont have a set day, i weigh myself roughly every 2-3 weeks or so. but i always weigh myself in my pjs, first thing in the morning, and always in the same spot on the bathroom floor, though i have tried other spots and theyre all the same, but i like one particular spot. i have weighed myself at different times on the same day, and have flucuated by upto 3-4 lbs. so i always do it first thing in morning now.