Today's event not showing on calendar

My wife has a blog for her kindergarten class, and in the sidebar there are calendars that show if the kids have school that day. This morning when she went to the blog, there was no link to today’s event and it showed on the calendar as black text (as opposed to orange text with a link, which would indicate there was an event). The event still shows under the Important Events list, so it seems something is wrong with the calendar widget, not the event.

The CSS looks okay; it is displaying the class as eventful-today, which should make the number bold and orange.

Her site is https://www.westmountkindergarten.ca.

Thanks,
Geoff