How to include additional info in day cells

The idea is simple:

1. Define a callback that takes two parameters like this:

   function getDateText(date, d)

   This function will receive the date object as the first parameter and the current date number (1..31) as the second (you can get it as well by calling date.getDate() but since it's very probably useful I thought I'd pass it too so that we can avoid a function call).

   This function must return the text to be inserted in the cell of the passed date. That is, one should at least "return d;".

2. Pass the above function as the "dateText" parameter to Calendar.setup.

The function could simply look like:

  function getDateText(date, d) {
    if (d == 12) {
      return "12th";
    } else if (d == 13) {
      return "bad luck";
    } /* ... etc ... */
  }

but it's easy to imagine that this approach sucks. For a better way, see the source of this page and note the usage of an externally defined "dateText" object which maps "date" to "date info", also taking into account the year and month. This object can be easily generated from a database, and the getDateText function becomes extremely simple (and static).

Cheers!