I'm sure you already know this, Gary, but I'll just elaborate on your suggestion for the benefit of anyone else who's reading the thread....

You have to be really careful with this option. If you just reformat the cells then it's important to understand that the times are still stored within the cell, it's just that they're not shown to the user. Of course that might be fine - or it may be a huge headache - depending on what you plan to do with them.