In astronomy, rotation was the turning of a celestial body around its axis. The length of one day was measured by the amount of time it took for a celestial body to complete a full rotation. (DS9: "Captive Pursuit")
This was one of the physical characteristics listed in a celestial body's file. (DIS: "The Sound of Thunder"; TNG: "Homeward")
The time of rotation for both Draygo IV and Vacca VI was listed in their planetary files. (TNG: "Homeward")