code: function(match, step) {
  				var isDoubled = doubled(match, step);
  				var size = [2, 3, isDoubled ? 4 : 2, isDoubled ? 4 : 2, 10, 11, 20]['oyYJ@!'.indexOf(match) + 1];
  				var digits = new RegExp('^-?\\d{1,' + size + '}');
  				var num = value.substring(iValue).match(digits);
  				if (!num) {
  					throw ($.calendars.local.missingNumberAt || $.calendars.regionalOptions[''].missingNumberAt).
  						replace(/\{0\}/, iValue);
  				}
  				iValue += num[0].length;
  				return parseInt(num[0], 10);
  			}
docs: Extract a number from the string value