获取当前月份的天数

  formatYearMonth(date) {
      const year = date.getFullYear();  //获取年
      const month = String(date.getMonth() + 1).padStart(2, "0"); //获取月
      return `${year}-${month}`;
    },
    
  getDaysInMonth(monthYearString) {
      const [year, month] = monthYearString.split("-").map(Number);
      return new Date(year, month, 0).getDate();  //获取当前月份的天数
    },