I get an .xslx template
Hi, there. I also get an .xslx template named "Online Yearly Calendar (Any Year).xlsx" along with the JPG image you describe.
When I open it with Microsoft Excel, it indeed loads a yearly calendar template that lets you select a year, and then it provides the months, dates, weeks, etc.
I think it does what it says on the tin. I think it's OK. It has limited value, but I don't think it is worthless.