常用的日期格式获取、转换

获取本周、本月、本年的起止时间范围

  1. import dayjs from 'dayjs'
  2. import type { Dayjs } from 'dayjs'
  4. type TimeFlag = 'ymd' | 'ym' | 'ymdt'
  6. export type RangeValue = [Dayjs, Dayjs]
  7. export type RangeStamp = [number, number]
  9. export function formatTime(time: string | number, flag: TimeFlag): string {
  10.   const timeObj = {
  11.     ymd: 'YYYY-MM-DD',
  12.     ym: 'YYYY-MM',
  13.     ymdt: 'YYYY-MM-DD HH:mm:ss'
  14.   }
  15.   const date = dayjs(+time).format(timeObj[flag])
  16.   console.log('🚀 ~ file: dateUtil.ts ~ line 13 ~ date', date)
  17.   return date
  18. }
  20. export function getTheWeek(): RangeStamp {
  21.   // 当天 0 点的时间戳
  22.   const dateStamp = new Date(new Date().toLocaleDateString()).getTime()
  24.   const weekStart = new Date(
  25.     dateStamp - 3600 * 1000 * 24 * (new Date().getDay() - 1)
  26.   )
  27.   const weekEnd = new Date(
  28.     dateStamp + 3600 * 1000 * 24 * (7 + 1 - new Date().getDay())
  29.   )
  30.   console.log(
  31.     '🚀 ~ file: dateUtil.ts ~ line 46 ~ getTheWeek ~ weekStart',
  32.     weekStart,
  33.     weekStart.getTime()
  34.   )
  35.   console.log(
  36.     '🚀 ~ file: dateUtil.ts ~ line 53 ~ getTheWeek ~ weekEnd',
  37.     weekEnd,
  38.     weekEnd.getTime()
  39.   )
  41.   const start_time = dayjs().startOf('week').format('YYYY-MM-DD HH:mm:ss')
  42.   const end_time = dayjs().endOf('week').format('YYYY-MM-DD HH:mm:ss')
  43.   console.log(
  44.     '🚀 ~ file: dateUtil.ts ~ line 40 ~ getTheWeek ~ start_time',
  45.     start_time,
  46.     dayjs(start_time).valueOf()
  47.   )
  48.   console.log(
  49.     '🚀 ~ file: dateUtil.ts ~ line 42 ~ getTheWeek ~ end_time',
  50.     end_time,
  51.     dayjs(end_time).valueOf()
  52.   )
  53.   const startStamp = dayjs(start_time).valueOf()
  54.   const endStamp = dayjs(end_time).valueOf()
  55.   return [startStamp, endStamp]
  56. }
  58. export function getTheMonth(): RangeStamp {
  59.   const date = new Date()
  60.   const monthStart = new Date(date.getFullYear(), date.getMonth(), 1) // 本月第一天
  61.   const monthEnd = new Date(date.getFullYear(), date.getMonth() + 1, 1) // 本月的最后一天(取下月1号0点)
  62.   console.log(
  63.     '🚀 ~ file: dateUtil.ts ~ line 61 ~ getTheMonth ~ monthStart',
  64.     monthStart,
  65.     monthStart.getTime()
  66.   )
  67.   console.log(
  68.     '🚀 ~ file: dateUtil.ts ~ line 71 ~ getTheMonth ~ monthEnd',
  69.     monthEnd,
  70.     monthEnd.getTime()
  71.   )
  73.   const start_time = dayjs().startOf('month').format('YYYY-MM-DD HH:mm:ss')
  74.   const end_time = dayjs().endOf('month').format('YYYY-MM-DD HH:mm:ss')
  75.   console.log(
  76.     '🚀 ~ file: dateUtil.ts ~ line 69 ~ getTheMonth ~ start_time',
  77.     start_time,
  78.     dayjs(start_time).valueOf()
  79.   )
  80.   console.log(
  81.     '🚀 ~ file: dateUtil.ts ~ line 71 ~ getTheMonth ~ end_time',
  82.     end_time,
  83.     dayjs(end_time).valueOf()
  84.   )
  86.   const startStamp = dayjs(start_time).valueOf()
  87.   const endStamp = dayjs(end_time).valueOf()
  88.   return [startStamp, endStamp]
  89. }
  91. export function getTheYear(): RangeStamp {
  92.   const date = new Date()
  93.   const startTime = new Date(date.getFullYear(), 0, 1) // 本月第一天
  94.   const endTime = new Date(date.getFullYear() + 1, 0, 1) // 本月的最后一天(取下月1号0点)
  96.   console.log(
  97.     '🚀 ~ file: dateUtil.ts ~ line 81 ~ getTheYear ~ start_time',
  98.     startTime,
  99.     startTime.getTime()
  100.   )
  101.   console.log(
  102.     '🚀 ~ file: dateUtil.ts ~ line 91 ~ getTheYear ~ end_time',
  103.     endTime,
  104.     endTime.getTime()
  105.   )
  107.   const start_time = dayjs().startOf('year').format('YYYY-MM-DD HH:mm:ss')
  108.   const end_time = dayjs().endOf('year').format('YYYY-MM-DD HH:mm:ss')
  109.   console.log(
  110.     '🚀 ~ file: dateUtil.ts ~ line 99 ~ getTheYear ~ start_time',
  111.     start_time,
  112.     dayjs(start_time).valueOf()
  113.   )
  114.   console.log(
  115.     '🚀 ~ file: dateUtil.ts ~ line 107 ~ getTheYear ~ end_time',
  116.     end_time,
  117.     dayjs(end_time).valueOf()
  118.   )
  120.   const startStamp = dayjs(start_time).valueOf()
  121.   const endStamp = dayjs(end_time).valueOf()
  122.   return [startStamp, endStamp]
  123. }

时间戳转换成格式化日期

  1. /*
  2.  * @Author: hhn
  3.  * @Date: 2020-07-05 16:57:46
  4.  * @lastEditTime: Do not edit
  5.  * @Description: timestamp缺省表示使用当前时间戳，formats默认格式是Y-m-d，例如2018-01-01。
  6.  * @FilePath: \codehub\study\studying\javascript\test.js
  7.  */
  8. var dateFormat = function(timestamp, formats) {
  9.     // formats格式包括
  10.     // 1. Y-m-d
  11.     // 2. Y-m-d H:i:s
  12.     // 3. Y年m月d日
  13.     // 4. Y年m月d日 H时i分
  14.     formats = formats || 'Y-m-d';
  16.     var zero = function(value) {
  17.         if (value < 10) {
  18.             return '0' + value;
  19.         }
  20.         return value;
  21.     };
  23.     var myDate = timestamp ? new Date(timestamp) : new Date();
  25.     var year = myDate.getFullYear();
  26.     var month = zero(myDate.getMonth() + 1);
  27.     var day = zero(myDate.getDate());
  29.     var hour = zero(myDate.getHours());
  30.     var minite = zero(myDate.getMinutes());
  31.     var second = zero(myDate.getSeconds());
  33.     return formats.replace(/Y|m|d|H|i|s/ig, function(matches) {
  34.         return ({
  35.             Y: year,
  36.             m: month,
  37.             d: day,
  38.             H: hour,
  39.             i: minite,
  40.             s: second
  41.         })[matches];
  42.     });
  43. };
  45. let date = new Date()
  46. console.log("date", date)
  47. console.log("dateFormat(date)", dateFormat(date))

image.png

时间戳转化为显示为多少分钟前，多少天前的处理

  1. /*
  2.  ** 时间戳显示为多少分钟前，多少天前的处理
  3.  ** eg.
  4.  ** console.log(dateDiff(1411111111111));  // 2014年09月19日
  5.  ** console.log(dateDiff(1481111111111));  // 9月前
  6.  ** console.log(dateDiff(1499911111111));  // 2月前
  7.  ** console.log(dateDiff(1503211111111));  // 3周前
  8.  ** console.log(dateDiff(1505283100802));  // 1分钟前
  9.  */
  10. var dateDiff = function(timestamp) {
  11.     // 补全为13位
  12.     var arrTimestamp = (timestamp + '').split('');
  13.     for (var start = 0; start < 13; start++) {
  14.         if (!arrTimestamp[start]) {
  15.             arrTimestamp[start] = '0';
  16.         }
  17.     }
  18.     timestamp = arrTimestamp.join('') * 1;
  20.     var minute = 1000 * 60;
  21.     var hour = minute * 60;
  22.     var day = hour * 24;
  23.     var halfamonth = day * 15;
  24.     var month = day * 30;
  25.     var now = new Date().getTime();
  26.     var diffValue = now - timestamp;
  28.     // 如果本地时间反而小于变量时间
  29.     if (diffValue < 0) {
  30.         return '不久前';
  31.     }
  33.     // 计算差异时间的量级
  34.     var monthC = diffValue / month;
  35.     var weekC = diffValue / (7 * day);
  36.     var dayC = diffValue / day;
  37.     var hourC = diffValue / hour;
  38.     var minC = diffValue / minute;
  40.     // 数值补0方法
  41.     var zero = function(value) {
  42.         if (value < 10) {
  43.             return '0' + value;
  44.         }
  45.         return value;
  46.     };
  48.     // 使用
  49.     if (monthC > 12) {
  50.         // 超过1年，直接显示年月日
  51.         return (function() {
  52.             var date = new Date(timestamp);
  53.             return date.getFullYear() + '年' + zero(date.getMonth() + 1) + '月' + zero(date.getDate()) + '日';
  54.         })();
  55.     } else if (monthC >= 1) {
  56.         return parseInt(monthC) + "月前";
  57.     } else if (weekC >= 1) {
  58.         return parseInt(weekC) + "周前";
  59.     } else if (dayC >= 1) {
  60.         return parseInt(dayC) + "天前";
  61.     } else if (hourC >= 1) {
  62.         return parseInt(hourC) + "小时前";
  63.     } else if (minC >= 1) {
  64.         return parseInt(minC) + "分钟前";
  65.     }
  66.     return '刚刚';
  67. };
  69. console.log("dateDiff()", dateDiff())

image.png

微信小程序版

  1. const formatMsgTime = function (dateStr) {
  2.       var dateObj = dateStr.replace(/T/g, ' ').replace(/\.[\d]{3}Z/, '').replace(/(-)/g, '/')
  3.       var targetDate = new Date(dateObj);
  4.       var year = targetDate.getFullYear();
  5.       var month = targetDate.getMonth() + 1;
  6.       var day = targetDate.getDate();
  7.       var hour = targetDate.getHours();
  8.       var minute = targetDate.getMinutes();
  9.       var second = targetDate.getSeconds();
  10.       var nowDate = new Date();
  11.       var now_new = Date.parse(nowDate.toString());
  12.       var milliseconds = 0;
  13.       var timeSpanStr;
  14.       milliseconds = now_new - targetDate;
  15.       if (milliseconds <= 1000 * 60 * 1) {
  16.           timeSpanStr = '刚刚';
  17.       }
  18.       else if (1000 * 60 * 1 < milliseconds && milliseconds <= 1000 * 60 * 60) {
  19.           timeSpanStr = Math.round((milliseconds / (1000 * 60))) + '分钟前';
  20.       }
  21.       else if (1000 * 60 * 60 * 1 < milliseconds && milliseconds <= 1000 * 60 * 60 * 24) {
  22.           timeSpanStr = Math.round(milliseconds / (1000 * 60 * 60)) + '小时前';
  23.       }
  24.       else if (1000 * 60 * 60 * 24 < milliseconds && milliseconds <= 1000 * 60 * 60 * 24 * 15) {
  25.           timeSpanStr = Math.round(milliseconds / (1000 * 60 * 60 * 24)) + '天前';
  26.       }
  27.       else if (milliseconds > 1000 * 60 * 60 * 24 * 15 && year == nowDate.getFullYear()) {
  28.           timeSpanStr = month + '-' + day;
  29.       } else {
  30.           timeSpanStr = year + '-' + month + '-' + day;
  31.       }
  32.       return timeSpanStr;
  33.   }
  34. module.exports = {
  35.     formatMsgTime: formatMsgTime
  36. }

使用方法

1，将上述代码保存为utils-days.js文件，放置在小程序公用目录里；
2，在需要使用的页面或者模块的js文件头部，导入该文件；
3，const utilsDays = require(‘../utils/utils-days’);
4， 使用该方法；

示例代码

  1. this.setData({
  2.     newDate: utilsDays.formatMsgTime(systemDate);
  3. })

获取当前日期的星期数 本年度第几周

  1. function getWeekNumber(date) {
  2.     // date 'yyyy-MM-dd'
  3.     date = new Date(date);
  4.     var date2 = new Date(date.getFullYear(), 0, 1);
  5.     var day1 = date.getDay();
  6.     if (day1 == 0) day1 = 7;
  7.     var day2 = date2.getDay();
  8.     if (day2 == 0) day2 = 7;
  9.     let d = Math.round((date.getTime() - date2.getTime() + (day2 - day1) * (24 * 60 * 60 * 1000)) / 86400000);
  11.     var getFullYear = date.getFullYear();
  12.     var getWeekNo = (Math.ceil(d / 7) + 1);
  13.     getWeekNo = (getWeekNo > 9 ? "" : "0") + getWeekNo;
  14.     //当周数大于52
  15.     if ((Math.ceil(d / 7) + 1) > 52) {
  17.         if (date.getMonth() == 11) {
  18.             // 还在当年12月份，则为当年第53周
  19.             return [getFullYear, "53"]
  20.         }
  21.         // 已经跨年，为下一年的第一周
  22.         return [getFullYear + 1, "01"]
  23.     }
  24.     return [getFullYear, getWeekNo];
  25. }

JS 获取某月的天数

一三五七八十腊，31天永不差，四六九十一，每月30天，惟有二月二十八，闰年要把日加一。

这里面还有个闰年的计算规则：四年一闰，百年不闰，四百年再闰。可以被4整除，但是不能被100整除，除非可以被400整除。

  1. function getMonthCountDay(year, month){
  2.     // year 为年份，month 为月份
  3. }
  4. [[2000,2],[2000,1],[2000,3],[2000,4],[2100,2],[2100,1],[2100,3],[2100,4],[2104,2],[2104,1],[2104,3],[2104,4],[2105,2],[2105,1],[2105,3],[2105,4],].map(v=>`${v} => ${getMonthCountDay.apply(null,v)}天`)

switch方案

  1. function getMonthCountDay (year, month) {
  2.   switch (month){
  3.     case 1:
  4.     case 3:
  5.     case 5:
  6.     case 7:
  7.     case 8:
  8.     case 10:
  9.     case 12:
  10.         return 31
  11.     case 4:
  12.     case 6:
  13.     case 9:
  14.     case 11:
  15.         return 30
  16.     case 2:
  17.         return year%400==0?(29):(year%4!=0||year%100==0?28:29)
  18.   }
  19. }

Date API 处理日期溢出特性（进位）

  1. function getMonthCountDay (year, month) {
  2.   return 32 - new Date(year, month-1, 32).getDate()
  3. }

Date API 处理日期溢出特性（退位方案）

  1. function getMonthCountDay (year, month) {
  2.   return new Date(year, month, 0).getDate()
  3. }

image.png

https://juejin.cn/post/6942640606732615694#heading-6