What I wanted was a simple, printable one page calendar for a specified month. I didn't like any of the many free calendar web sites so created my own one page calendar.
I've also created a page that displays small calenders showing dates for a specific year. This full year calendar I created to help with date calculations.
This week-of-year page is similar, showing a year of calendars, each week with a "week of year" number for use in debugging date calculations.