Consider the experience of this web application.

The image is from a web site which lists special events at a historical site. I clicked on Saturday the 27th to see if there were any special events planned. The text that returned doesn't match well with my action and also is anything but friendly: "No records matched your search criteria."

1. I really didn't do a search from my perspective. I just looked at the calendar to see if any special events were planned for this weekend. Yes, to a geek who knows, it probably checked some database table somewhere -- but as a user, I couldn't care less.
2. What records? There aren't any records.
3. Criteria? Come on. Who talks that way in every day conversation?

Here's how I would have fixed it:

"There aren't any special events planned for May 27th."

That alone would have been a vast improvement. But, we could do more.

"On June 4th, a special day of appreciation is planned for all visitors, and as a thank you, the admission price is reduced to only $3!"

By looking ahead for the next available special event, we would provide the user with the information they really want to know, like maybe instead of going tomorrow, they should wait a week and go as the admission price will be less.

In the US, it's uncommon to see a calendar that way -- so I'm not sure why they've chosen to display the calendar with Saturday and Sunday displayed side by side. If they weren't a different color, I probably would have been confused (they did something abnormal, so they had to fix that abnormality with a different, non-typical display technique).