After two weeks of non-stop sightseeing, the cruise's sea days were the most relaxing part of the trip.

Astronomers measured the planet's rotation over several sidereal days to determine its axial tilt.

The resort reported a record number of skier days this season thanks to the unusually long snowpack.

The professor scheduled extra office hours on speech days to help nervous students rehearse.

During the summer, we spent many stellar days stargazing along the coast.

Local fishermen schedule their trips around the tide days to ensure safe navigation.

During the Victory Days, people gathered in the square to celebrate the end of the long conflict.

During the canicular days, the village well was crowded from dawn until dusk.

Our mission spanned ten Earth days, during which the crew conducted extensive experiments.

We estimated the project would require 120 woman-days to complete.