Any time during the day or night when one's body makes a strong suggestion for the owner of said body to engage in the act of fecal excretion; especially via the Anus.
"Oh wow, I can feel it, it's almost poo-thirty", or, "What time is it?....it's almost poo-thirty".
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2million.