code: function(source, params) {
  				var format = ($.calendarsPicker.curInst ?
  					$.calendarsPicker.curInst.get('dateFormat') :
  					$.calendarsPicker.defaultOptions.dateFormat);
  				$.each(params, function(index, value) {
  					source = source.replace(new RegExp('\\{' + index + '\\}', 'g'),
  						value.formatDate(format) || 'nothing');
  				});
  				return source;
  			}
docs: Format a validation error message involving dates.
  @param source {string} The error message.
  @param params {Date[]} The dates.
  @return {string} The formatted message.