code: function defaultParse(str) {
    if (typeof str !== 'string') {
      return undefined;
    }
    var split = str.split('-');
    if (split.length !== 3) {
      return undefined;
    }
    var year = parseInt(split[0], 10);
    var month = parseInt(split[1], 10) - 1;
    var day = parseInt(split[2], 10);
    if (isNaN(year) || String(year).length > 4 || isNaN(month) || isNaN(day) || day <= 0 || day > 31 || month < 0 || month >= 12) {
      return undefined;
    }
  
    return new Date(year, month, day);
  }
docs: The default function used to parse a String as Date, passed to the `parse`
  prop.
  @param {String} str
  @return {Date}