关于时间常用的一些函数的封装

保存一些常用的时间函数的封装

1、首先是时间格式化函数

// 时间格式化函数 formatDate(new Date(),"yyyy-MM-dd hh:mm:ss");
export function formatDate(date, fmt) {
  if (/(y+)/.test(fmt)) {
    fmt = fmt.replace(RegExp.$1, (date.getFullYear() + '').substr(4 - RegExp.$1.length));
  }
  let o = {
    'M+': date.getMonth() + 1,
    'd+': date.getDate(),
    'h+': date.getHours(),
    'm+': date.getMinutes(),
    's+': date.getSeconds()
  };
  for (let k in o) {
    if (new RegExp(`(${k})`).test(fmt)) {
      let str = o[k] + '';
      fmt = fmt.replace(RegExp.$1, (RegExp.$1.length === 1) ? str : padLeftZero(str));
    }
  }
  return fmt;
};

这基本上也算是最常用的了，就是把一个时间对象，转换成为一个字符串时间

2、获取一下常用的时间字符串，比方说，这周的开始时间，这周的结束时间（周六为一周的最后一天）

var now = new Date(); //当前日期
var nowDayOfWeek = now.getDay(); //今天本周的第几天
var nowDay = now.getDate(); //当前日
var nowMonth = now.getMonth(); //当前月
var nowYear = now.getYear(); //当前年
nowYear += (nowYear < 2000) ? 1900 : 0; //
var lastMonthDate = new Date(); //上月日期
lastMonthDate.setDate(1);
lastMonthDate.setMonth(lastMonthDate.getMonth() - 1);
var lastYear = lastMonthDate.getFullYear();
var lastMonth = lastMonthDate.getMonth();
// console.log(lastYear)
//格式化日期：yyyy-MM-dd
function formatDateOther(date) {
  var myyear = date.getFullYear();
  var mymonth = date.getMonth() + 1;
  var myweekday = date.getDate();
  if (mymonth < 10) {
    mymonth = "0" + mymonth;
  }
  if (myweekday < 10) {
    myweekday = "0" + myweekday;
  }
  return (myyear + "-" + mymonth + "-" + myweekday);
}
//获得某月的天数
function getMonthDays(myMonth) {
  var monthStartDate = new Date(nowYear, myMonth, 1);
  var monthEndDate = new Date(nowYear, myMonth + 1, 1);
  var days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24);
  return days;
}
//获得本季度的开始月份
function getQuarterStartMonth() {
  var quarterStartMonth = 0;
  if (nowMonth < 3) {
    quarterStartMonth = 0;
  }
  if (2 < nowMonth && nowMonth < 6) {
    quarterStartMonth = 3;
  }
  if (5 < nowMonth && nowMonth < 9) {
    quarterStartMonth = 6;
  }
  if (nowMonth > 8) {
    quarterStartMonth = 9;
  }
  return quarterStartMonth;
}
//获得本周的开始日期
function getWeekStartDate() {
  var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);
  return formatDateOther(weekStartDate);
}
//获得本周的结束日期
function getWeekEndDate() {
  var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));
  return formatDateOther(weekEndDate);
}
//获得上周的开始日期
function getLastWeekStartDate() {
  var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 7);
  return formatDateOther(weekStartDate);
}
//获得上周的结束日期
function getLastWeekEndDate() {
  var weekEndDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 1);
  return formatDateOther(weekEndDate);
}
//获得本月的开始日期
function getMonthStartDate() {
  var monthStartDate = new Date(nowYear, nowMonth, 1);
  return formatDateOther(monthStartDate);
}
//获得本月的结束日期
function getMonthEndDate() {
  var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));
  return formatDateOther(monthEndDate);
}
//获得上月开始时间
function getLastMonthStartDate() {
  var lastMonthStartDate = new Date(lastYear, lastMonth, 1);
  return formatDateOther(lastMonthStartDate);
}
//获得上月结束时间
function getLastMonthEndDate() {
  var lastMonthEndDate = new Date(lastYear, lastMonth, getMonthDays(lastMonth));
  return formatDateOther(lastMonthEndDate);
}
//获得本季度的开始日期
function getQuarterStartDate() {
  var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);
  return formatDateOther(quarterStartDate);
}
//或的本季度的结束日期
function getQuarterEndDate() {
  var quarterEndMonth = getQuarterStartMonth() + 2;
  var quarterStartDate = new Date(nowYear, quarterEndMonth, getMonthDays(quarterEndMonth));
  return formatDateOther(quarterStartDate);
}