Looping an animated procedural texture

Do animated procedural textures ever reach a point where they will repeat? and if so, how do you calculate the number of frames needed to make a looping animation?

Procedural textures do not repeat normally, but there is a trick to get them to.

If you set the mapping to an empty, offset the empty by several units, then rotate that empty, then the procedural texture will loop.

Colin Litster figured this out: http://wiki.blender.org/index.php/BSoD/Introduction_to_Materials/exercise_2#Map_Input_to_an_Empty

Thanks a lot for the info, I will check into that.