Ajax calendar – sunday smaller than other days

Is there any way to adjust the adjust calendar so that all pages are the same width.

The width of the Sunday column is less than half that of the other days

We are using the Creativix them and I have already widened the main area by 100px. This helped a bit

https://www.mensa.org.au/home/calendar/

Thanks

https://www.ads-software.com/extend/plugins/ajax-event-calendar/