Measuring time with planetary rotations and orbits works for those who live their lives on a single planet. Spacers, who spend their lives on ships or spacestations, need other ways.

Like Centre, they use the standard second, standard minute, standard day and standard year. There are 60 standard seconds in a standard minute; 1440 standard minutes in a standard day; 360 standard days in a standard year.

Many spacers also use divs. There are 30 standard days in a div and 12 divs in a standard year.

The calendar is measured from the founding of Centre. At the start of Cast Adrift it is year 23,242.
Night is 360 minutes long
Morning is 360 minutes long
Afternoon is 360 minutes long
Evening is 360 minutes long