js 如何获取某一个月的第一天是周几 calendar ??? padding dates // day = 1 const firstMonthDate = new Date(year + month + 1); const weekDays = ['周日','周1','周2','周3','周4','周5','周6']; const firstMonthDate = weekDays[firstMonthDate.getDay()] demo const weekDays = ['周日','周