A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
This is not really the answer John but 59 seconds is the longest time you can enter in the ribbon (bizarrely PowerPoint can in fact run longer animations if you add the time in code or by dragging the timeline).
So if you enter 75 SECONDS it would switch to 59.00. Obviously 00.75 is not 75 seconds but my guess is your PC thinks it is (It doesn't happen here in 2016)
If you enter 00.50 for an animation does it actually run for 0.5 sec?