code: function(match, shortNames, longNames, step) {
  				var names = (doubled(match, step) ? longNames : shortNames);
  				for (var i = 0; i < names.length; i++) {
  					if (value.substr(iValue, names[i].length).toLowerCase() === names[i].toLowerCase()) {
  						iValue += names[i].length;
  						return i + calendar.minMonth;
  					}
  				}
  				throw ($.calendars.local.unknownNameAt || $.calendars.regionalOptions[''].unknownNameAt).
  					replace(/\{0\}/, iValue);
  			}
docs: Extract a name from the string value and convert to an index