Hi Jeff,
The columns are defined by the number of repetitions displayed in "stack" of repeating fields. You can reduce the number of repetitions to 3 in layout mode, and then increase their width to fill the available space in the portal. They are already set to "auto-resize." When I do this, I double click on the repeating fields to the far right, so when I reduce the number of repetitions in the inspector, it reveals the next repeating field in the stack and I just work my way down until there all at 3. I then group them and stretch them back to the right.
There's some helpful documentation on working on the different calendar tabs in layout mode, including a few videos:
http://www.seedcode.com/pmwiki/pmwiki.p ... lendarTabsAs always, when making these kinds of changes, make sure you have a good back-up to revert to in case you get into trouble.
hth,
Jason