Historians often compare different time periods to understand social change.

The historian compared artifacts from different periods of time to understand cultural changes.

Astronomers compared the sidereal periods of the two exoplanets to understand their orbital resonances.

The conference schedule includes several question periods after each presentation.

Employees should be aware that different departments may have different notice periods.

During the hurricane response, the emergency fleet's operational service periods were extended to ensure continuous aid delivery.

Astronomers measured the sidereal orbital periods of the newly discovered exoplanets to refine their models.

Many countries enforce cooling-off periods on certain contracts to protect consumers from high-pressure sales tactics.

Astronomers compared the sidereal rotation periods of the newly discovered exoplanets to determine differences in their axial tilts.

In dual-task experiments, participants often exhibit psychological refractory periods when responding to closely timed stimuli.