陪玩源码，与时间、日期相关的代码分析

获取上/下个月日期

// 下个月
let date = new Date(this.startDate);
let nextMonthDate = date.setMonth(date.getMonth() + 1);
this.endDate = dateFormat("YYYY-MM-DD", new Date(nextMonthDate));

// 上个月
let lastMonthDate = date.setMonth(date.getMonth() - 1);

获取前/后7天日期

// 前7天
let date = new Date(this.startDate);
let afterDate = date.setDate(date.getDate() + 6);
this.endDate = dateFormat("YYYY-MM-DD", new Date(afterDate));

// 后7天
let afterDate = date.setDate(date.getDate() - 6);

一周日期

let weeks=["周一","周二","周三","周四","周五","周六","周日"];
for (let i = 0; i<7; i++){
  let date = new Date();
  let index = date.getDay() ? date.getDay() - 1 : 6;
  let nowDate = date.setDate(date.getDate() - index + i);
  let formatDate = dateFormat("MM-DD", new Date(nowDate));
  let week = weeks[i]; 
  let weekDate = `${formatDate}(${week})`;
  this.weekDateColumns.push(weekDate);
}

当月第一天和最后一天

// 第一天
let date = new Date();
date.setDate(1);
console.log(dateFormat("YYYY-MM-DD", date));

// 最后一天
let date = new Date();
let lastDay = new Date(date.getFullYear(), date.getMonth() + 1, 0);
console.log(dateFormat("YYYY-MM-DD", lastDay));

计算传入时间与当前时间相差的秒数

function convertStrToTime (time) {
  let nowTime = new Date().getTime();
  let date = new Date();
  let arr = time.split(":");
  date.setHours(parseInt(arr[0]));
  date.setMinutes(parseInt(arr[1]));
  let endTime = new Date(date).getTime();
  let ret = Math.ceil((endTime - nowTime) / 1000);
  return ret;
}