The rotation time of a structure or module is the amount of time needed for a moving part to complete one circular rotation or revolution when turning at maximum speed. This field can be applied to a structure as a whole when the structure itself is generally thought of as a moving object, and when no significant turning part of the structure deviates from one rotation time (for example in the case of an amusement ride). In the case of a revolving floor of a building, the rotation time should be applied to the floor itself.

This is a measurement of the installation as it runs, not a property of the building. Lift speeds are reset, drives are slowed as they age, and a roof that opened in ten minutes when new can take longer later, so a duration belongs to the date it was taken on.

Where several installations exist, the value describes the one named in the field and not an average of them.