Here's a flexible, simple pop-up calendar
written to work across browsers. It's fully
commented and customisable for language,
colours and date format. The pop-up displays
a month at a time from a specified range of
years. The optional year, month and day input
determines the initial month displayed. The
year can be in two or four digits while the
month can be digits or a month name
abbreviation that can easily be set up for
non-English languages. This is ideal for
combination with server-side technologies to
produce a professional application.
Version 2.4 now allows days of the week,
dates and date ranges to be disabled dynamically.