This HTML page is an attempt to faithfully recreate the visual layout of my house's monthly calendar that we usually make by hand.
Open the HTML page in Google Chrome. File -> Print -> Destination: Save as PDF -> Save. This seems to render slightly differently (extending to the end of the page) than when a printer is selected and Open PDF in Preview is clicked.
From macOS Preview. File -> Print. Under "Paper Size", hover over "US Letter", but select "US Letter Borderless". Then print.