Ananta Shesha: "Intending to go outside to collect samples of stone and as w…"

Intending t☉ g☉ ☉utside t☉ c☉llect samples ☉f st☉ne and as well as a little bit ☉f water. H☉w can y☉u tr☉lls tell if it's day ☉r night ☉utside?