Hey Steve!
Real sorry for the trouble here – I took a look at your site and unfortunately found that these overlapping issues arise from various styles inherited from your theme.
That does not mean we can’t help here 🙂 Just pointing out the source of the problem; and the fact that follows from it, which is that unfortunately the only way to fix this is to use some custom CSS.
There are a number of approaches that could theoretically work here. One example would be to widen your entire theme – but this is clearly a big change that could have many many consequences.
A smaller and simpler change that would be just as effective would be to decrease the font-size of the day titles ever so slightly. For example, try pasting the following CSS at the bottom of your theme’s style.css:
.tribe-events-calendar thead th {
font-size: 1em !important;
}
1em is just an example, but you can change it to any size you’d like.
Here’s how 1em font size makes things look on your site:

I hope that helps! 😀
Cheers,
George