Main toolbar > Curve Editor (Open) > Time Ruler (below right-hand pane)

Graph Editors menu > Track View - Curve Editor/Track View - Dope Sheet > Time Ruler (below right-hand pane)

The time ruler at the bottom of the Track View Key window measures time. Markings on the time ruler reflect the settings in the Time Configuration dialog. You can drag the time ruler vertically in the Key window to align it with any track.