js 获取某月第一天和最后一天

1、获取某月第一天和最后一天日期

function getDateByMonth (timeStamp) {
  let inDate = new Date(timeStamp)
  let year = inDate.getFullYear()
  let month = inDate.getMonth()
  let startTime = new Date(year, month, 1).getTime()
  let endTime =  new Date(year, month + 1, 0).getTime()
  return {
    startTime: startTime,
    endTime: endTime
  }
}

2、获取某月第一天和最后一天时间戳

/** 根据时间戳 获取其月开始时间戳和结束时间戳 */
function getTimeStamp (timeStamp) {
  let inDate = new Date(timeStamp)
  let year = inDate.getFullYear()
  let month = inDate.getMonth()
  let startTime = new Date(year, month, 1).getTime()
  let endTime =  new Date(year, month + 1, 1).getTime() - 1
  return {
    startTime: startTime,
    endTime: endTime
  }
}