js 时间处理

时间戳转formdate格式 13 || 16 位

1    function timeStampToFormdate(timestamp) {
2        if (!timestamp) {
3            return ''
4        }
5        var date = timestamp.toString().length == "13" ? new Date(timestamp) : new Date(timestamp * 1000); //时间戳为10位需*1000，时间戳为13位的话不需乘1000
6        var Y = date.getFullYear() + "-";
7        var M = (date.getMonth() + 1 < 10 ? "0" + (date.getMonth() + 1) : date.getMonth() + 1) + "-";
8        var D = (date.getDate() < 10 ? '0' + date.getDate() : date.getDate());
9        var h = date.getHours() < 10 ? "0" + date.getHours() + ":" : date.getHours() + ":";
10        var m = date.getMinutes() < 10 ? "0" + date.getMinutes() + ':' : date.getMinutes() + ":";
11        var s = date.getSeconds() < 10 ? "0" + date.getSeconds() : date.getSeconds();
12        return Y + M + D + ' ' + h + m + s;
13    }
14    console.log(timeStampToFormdate(new Date().getTime()));

获取距离当前时间多少天前的时间

1 function manyDayBeforeNowDay(days) {
2        if (days * 1) {
3            return timeStampToFormdate(new Date().getTime() - days * 60 * 60 * 24 * 1000)
4        } else {
5            return ''
6        }
7    }
8    console.log(manyDayBeforeNowDay(2));

时间格式化返回年月日时分秒 格式自己拼

1/**
2*如果没有传入时间，就返回当前时间的格式化数据
3*/
4function dateFormat(date) {
5!date && date=new Date();
6  if (date) {
7    let newDate = new Date(date);
8    let n = newDate.getFullYear();
9    let y = (newDate.getMonth() + 1 < 10 ? '0' + (newDate.getMonth() + 1) : newDate.getMonth() + 1);
10    let r = (newDate.getDate() < 10 ? '0' + newDate.getDate() : newDate.getDate());
11    let s = (newDate.getHours() < 10 ? '0' + newDate.getHours() : newDate.getHours());
12    let f = (newDate.getMinutes() < 10 ? '0' + newDate.getMinutes() : newDate.getMinutes());
13    let m = (newDate.getSeconds() < 10 ? '0' + newDate.getSeconds() : newDate.getSeconds());
14    let format = {
15      n: n,
16      y: y,
17      r: r,
18      s: s,
19      f: f,
20      m: m,
21    }
22    return format
23  }
24}

获取当前星期几

1function getWeekDate() {
2  var now = new Date();
3  var day = now.getDay();
4  var weeks = new Array(
5    "星期日",
6    "星期一",
7    "星期二",
8    "星期三",
9    "星期四",
10    "星期五",
11    "星期六"
12  );
13  var week = weeks[day];
14  return week;
15}

根据当前年的第几天 获取所在的日期

1/**
2 * @param {Number} year 哪年
3 * @param {Number} day  哪天
4 */
5function dayToMD(year, day) {
6  if (year && day && day < 367) {
7    var isrunnian = (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0;
8    var rules = [31, isrunnian ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
9    for (var i = 0; i < rules.length; i++) {
10      if (rules[i] >= day) {
11        return (i + 1 < 10 ? ("0" + (i + 1)) : (i + 1)) + '-' + (day < 10 ? ("0" + day) : day);
12      }
13      day -= rules[i];
14    }
15  }
16}

获取所在周

记录一下 ，计算规则比较怪。产品这么要求，╮(╯▽╰)╭

1/**
2 * 获取当前天所在的周
3 * 规则：按照日历上一行为一周。以当前年第一个周一所在的日期为当前年的起点
4 * 如果当前日期>=起点，计算公式：Math.ceil((当前天数-(起点-1))/7)
5 * 如果当前日期<起点 ，计算公式：Math.ceil((上一年的天数-(上一年起点-1)+当前日期天数)/7)
6 * 返回结果 2020-1  2020年第几周
7 * 头秃
8 */
9
10function weekFilter() {
11  function yearDays(leapY) {
12    var strleapYis =
13      (leapY % 4 == 0 && leapY % 100 != 0) || leapY % 400 == 0;
14    if (strleapYis) {
15      strleapYis = 366;
16    } else {
17      strleapYis = 365;
18    }
19    return strleapYis;
20  }
21  function getWeekDay(year) {
22    var d = new Date();
23    d.setFullYear(year, 0);
24    for (var i = 1; i <= 31; i++) {
25      d.setDate(i);
26      if (d.getDay() == 1) break;
27    }
28    d.setFullYear(year, 0, i);
29    // return year + "-" + "01-" + (i >= 10 ? i :( "0" + i));
30    return i;
31  }
32  let nowDay = Math.ceil(
33    (new Date() - new Date(new Date().getFullYear().toString())) /
34      (24 * 60 * 60 * 1000)
35  );
36  let nowYear = new Date().getFullYear();
37  let nowWeek;
38  if (nowDay >= getWeekDay(nowYear)) {
39    nowWeek = Math.ceil((nowDay - (getWeekDay(nowYear) - 1)) / 7);
40    return `${nowYear}-${nowWeek}`
41  } else {
42    nowWeek = Math.ceil(
43      (yearDays(nowYear - 1) - (getWeekDay(nowYear - 1) - 1) + nowDay) / 7
44    );
45    return `${nowYear - 1}-${nowWeek}`
46  }
47}