This period varies from 10 to 30 years, or occasionally until age 95.

The period of servitude varies from a few months to life.

The period of development varies with temperature and lasts for two to three weeks.

This period varies from a few hours for some individuals up to around two weeks.

A period may vary in time, but is usually 30-90 minutes long.

The period of validity may vary from just seconds to days or even weeks.

This period of time may vary from one to three months.

The period certainly varies with the season; but here is one case exactly noted.

Intensity and period varied; the balance, the mean, did not.

This period may vary from a few days to weeks, months, or years.