public/javascripts/yui/calendar/calendar.js
function(strId) {
        var idx = -1,
            li = strId.lastIndexOf("_cell");

        if (li > -1) {
            idx = parseInt(strId.substring(li + 5), 10);
        }

        return idx;
    }
function(strId) {
        var idx = -1,
            li = strId.lastIndexOf("_cell");

        if (li > -1) {
            idx = parseInt(strId.substring(li + 5), 10);
        }

        return idx;
    }
function ( strId ) { var idx = - 1 , li = strId . lastIndexOf ( "_cell" ) ; if ( li > - 1 ) { idx = parseInt ( strId . substring ( li + 5 ) , 10 ) ; } return idx ; }
Given the id used to mark each Calendar cell, this method
extracts the index number from the id.

@param {String} strId The cell id
@return {Number} The index of the cell, or -1 if id does not contain an index number
Given the id used to mark each Calendar cell this method extracts the index number from the id .