This widget (version 1.0, by Eran Miller) comes with no documentation for the non-programmer. So, having installed it, I’ll try typing its “shortcode” (the word “calendar” between square brackets) as instructed, and see what happens.

Update: Aha, it caused a calendar to appear below (that is, at the point in the post where I inserted the code). It was a typical month-view grid (with buttons for navigating to other months) and populated with an event that was entered by default during installation (that is, it displayed “Ajax Event Calendar [v1.0] successfully installed!” under today’s date). Some elements of the plugin’s appearance have settings I could change.

Also, by creating a page (instead of a post) and typing the shortcode there, I could make this calendar appear as a fixed option in the site’s navigation menu. (If I’d left it in this post, it would’ve been pushed off the page eventually by newer posts.)

I’ve uninstalled the widget, because I found the appearance unappealing. Also, the options for recurring events are unsatisfactory; for instance, it requres one to specify the exact number of days between occurrences, which of course won’t work for typical monthly events.