如何计算两个日期之间的年数？

Question

我想知道两个日期之间的年数。我可以得到这两天之间的天数，但是如果我把它除以365，结果是不正确的，因为有些年份有366天。

这是我获取日期差异的代码：

var birthday = value;//format 01/02/1900
var dateParts = birthday.split("/");

var checkindate = new Date(dateParts[2], dateParts[0] - 1, dateParts[1]);   
var now = new Date();
var difference = now - checkindate;
var days = difference / (1000*60*60*24);

var thisyear = new Date().getFullYear();
var birthyear = dateParts[2];

    var number_of_long_years = 0;
for(var y=birthyear; y <= thisyear; y++){   

    if( (y % 4 == 0 && y % 100 == 0) || y % 400 == 0 ) {

                    number_of_long_years++;             
    }
}   

日计数完美无缺。我试图在366天的年份添加额外的日子，我正在做这样的事情：

var years = ((days)*(thisyear-birthyear))
            /((number_of_long_years*366) + ((thisyear-birthyear-number_of_long_years)*365) );

我得到了年份数。这是正确的，还是有更好的方法来做到这一点？

Answer 1

时尚的基础javascript功能。

 function calculateAge(birthday) { // birthday is a date
   var ageDifMs = Date.now() - birthday.getTime();
   var ageDate = new Date(ageDifMs); // miliseconds from epoch
   return Math.abs(ageDate.getUTCFullYear() - 1970);
 }

Answer 2

可能不是你想要的答案，但是在2.6kb，我不会尝试重新发明轮子，我会使用像moment.js这样的东西。没有任何依赖。

diff方法可能就是您想要的：http://momentjs.com/docs/#/displaying/difference/

Answer 3

没有for-each循环，不需要额外的jQuery插件...只需调用以下函数..来自Difference between two dates in years

        function dateDiffInYears(dateold, datenew) {
            var ynew = datenew.getFullYear();
            var mnew = datenew.getMonth();
            var dnew = datenew.getDate();
            var yold = dateold.getFullYear();
            var mold = dateold.getMonth();
            var dold = dateold.getDate();
            var diff = ynew - yold;
            if (mold > mnew) diff--;
            else {
                if (mold == mnew) {
                    if (dold > dnew) diff--;
                }
            }
            return diff;
        }

Answer 4

我使用以下内容进行年龄计算。

我把它命名为gregorianAge()，因为这个计算给出了我们如何用格里高利历来表示年龄。即如果月份和日期在出生年份的月份和日期之前，则不计算结束年份。

/**
 * Calculates human age in years given a birth day. Optionally ageAtDate
 * can be provided to calculate age at a specific date
 *
 * @param string|Date Object birthDate
 * @param string|Date Object ageAtDate optional
 * @returns integer Age between birthday and a given date or today
 */
function gregorianAge (birthDate, ageAtDate) {
  // convert birthDate to date object if already not
  if (Object.prototype.toString.call(birthDate) !== '[object Date]')
    birthDate = new Date(birthDate);

  // use today's date if ageAtDate is not provided
  if (typeof ageAtDate == "undefined")
    ageAtDate = new Date();

  // convert ageAtDate to date object if already not
  else if (Object.prototype.toString.call(ageAtDate) !== '[object Date]')
    ageAtDate = new Date(ageAtDate);

  // if conversion to date object fails return null
  if (ageAtDate == null || birthDate == null)
    return null;


  var _m = ageAtDate.getMonth() - birthDate.getMonth();

  // answer: ageAt year minus birth year less one (1) if month and day of
  // ageAt year is before month and day of birth year
  return (ageAtDate.getFullYear()) - birthDate.getFullYear()
    - ((_m < 0 || (_m === 0 && ageAtDate.getDate() < birthDate.getDate()))?1:0)
}

Answer 5

很少过时，但这是一个你可以使用的功能！

function calculateAge(birthMonth, birthDay, birthYear) {
    var currentDate = new Date();
    var currentYear = currentDate.getFullYear();
    var currentMonth = currentDate.getMonth();
    var currentDay = currentDate.getDate(); 
    var calculatedAge = currentYear - birthYear;

    if (currentMonth < birthMonth - 1) {
        calculatedAge--;
    }
    if (birthMonth - 1 == currentMonth && currentDay < birthDay) {
        calculatedAge--;
    }
    return calculatedAge;
}

var age = calculateAge(12, 8, 1993);
alert(age);

Answer 6

使用纯JavaScript Date()，我们可以像下面那样计算年数

document.getElementById('getYearsBtn').addEventListener('click', function () {
  var enteredDate = document.getElementById('sampleDate').value;
  // Below one is the single line logic to calculate the no. of years...
  var years = new Date(new Date() - new Date(enteredDate)).getFullYear() - 1970;
  console.log(years);
});

<input type="text" id="sampleDate" value="1980/01/01">
<div>Format: yyyy-mm-dd or yyyy/mm/dd</div><br>
<button id="getYearsBtn">Calculate Years</button>

Answer 7

是的，moment.js非常适合这个：

var moment = require('moment');
var startDate = new Date();
var endDate = new Date();
endDate.setDate(endDate.getFullYear() + 5); // Add 5 years to second date
console.log(moment.duration(endDate - startDate).years()); // This should returns 5

Answer 8

for(var y=birthyear; y <= thisyear; y++){ 

if( (y % 4 == 0 && y % 100 == 0) || y % 400 == 0 ) { 
 days = days-366;
 number_of_long_years++; 
} else {
    days=days-365;
}

year++;

}

---

你能尝试这种方式吗？

Answer 9

function getYearDiff(startDate, endDate) {
    let yearDiff = endDate.getFullYear() - startDate.getFullYear();
    if (startDate.getMonth() > endDate.getMonth()) {
        yearDiff--;
    } else if (startDate.getMonth() === endDate.getMonth()) {
        if (startDate.getDate() > endDate.getDate()) {
            yearDiff--;
        } else if (startDate.getDate() === endDate.getDate()) {
            if (startDate.getHours() > endDate.getHours()) {
                yearDiff--;
            } else if (startDate.getHours() === endDate.getHours()) {
                if (startDate.getMinutes() > endDate.getMinutes()) {
                    yearDiff--;
                }
            }
        }
    }
    return yearDiff;
}

alert(getYearDiff(firstDate, secondDate));

Answer 10

let currentTime = new Date().getTime();
let birthDateTime= new Date(birthDate).getTime();
let difference = (currentTime - birthDateTime)
var ageInYears=difference/(1000*60*60*24*365)

Answer 11

您可以使用时间戳获取准确的年龄

`const getAge = (dateOfBirth, dateToCalculate = new Date()) => {
    const dob = new Date(dateOfBirth).getTime();
    const dateToCompare = new Date(dateToCalculate).getTime();
    const age = (dateToCompare - dob) / (365 * 24 * 60 * 60 * 1000);
    return Math.floor(age);
};`

Answer 12

function dateDiffYearsOnly( dateNew,dateOld) {
   function date2ymd(d){ w=new Date(d);return [w.getFullYear(),w.getMonth(),w.getDate()]}
   function ymd2N(y){return (((y[0]<<4)+y[1])<<5)+y[2]} // or 60 and 60 // or 13 and 32 // or 25 and 40 //// with ...
   function date2N(d){ return ymd2N(date2ymd(d))}

   return  (date2N(dateNew)-date2N(dateOld))>>9
}

测试：

dateDiffYearsOnly(Date.now(),new Date(Date.now()-7*366*24*3600*1000));
dateDiffYearsOnly(Date.now(),new Date(Date.now()-7*365*24*3600*1000))

Answer 13

getYears(date1, date2) {
let years = new Date(date1).getFullYear() - new Date(date2).getFullYear();
let month = new Date(date1).getMonth() - new Date(date2).getMonth();
let dateDiff = new Date(date1).getDay() - new Date(date2).getDay();
if (dateDiff < 0) {
    month -= 1;
}
if (month < 0) {
    years -= 1;
}
return years;
}

Answer 14

Bro，moment.js在这方面很棒： diff方法就是您想要的：http://momentjs.com/docs/#/displaying/difference/

下面的函数返回从年份到当前年份的年份数组。

const getYears = (from = 2017) => {
  const diff = moment(new Date()).diff(new Date(`01/01/${from}`), 'years') ;
  return [...Array(diff >= 0 ? diff + 1 : 0).keys()].map((num) => {
    return from + num;
  });
}

console.log(getYears(2016));

<script src="https://momentjs.com/downloads/moment.js"></script>

Answer 15

如果您正在使用时刻

export abstract class TransactionConstructor {

  protected constructor(private readonly conversionService: ConversionService,
                        private readonly formatService: FormatService) {
  }
}

@Injectable()
export class TransactionConstructorBTC extends TransactionConstructor {

  protected constructor(conversionService: ConversionService,
                        formatservice: FormatService) {
    super(conversionService, formatService);
  }

  public create() {
    return new TransactionConstructorBTC();
  }
}

@Injectable()
export class TransactionConstructorETH extends TransactionConstructor {

  protected constructor(conversionService: ConversionService,
                        formatservice: FormatService) {
    super(conversionService, formatService);
  }

  public create() {
    return new TransactionConstructorETH();
  }
}

Answer 16

getAge(month, day, year) {
    let yearNow = new Date().getFullYear();
    let monthNow = new Date().getMonth() + 1;
    let dayNow = new Date().getDate();
    if (monthNow === month && dayNow < day || monthNow < month) {
      return yearNow - year - 1;
    } else {
      return yearNow - year;
    }
  }

Answer 17

也许我的函数可以更好地解释如何以一种简单的方式来做到这一点，而无需循环，计算和/或库

function checkYearsDifference(birthDayDate){
    var todayDate = new Date();
    var thisMonth = todayDate.getMonth();
    var thisYear = todayDate.getFullYear();
    var thisDay = todayDate.getDate();
    var monthBirthday = birthDayDate.getMonth(); 
    var yearBirthday = birthDayDate.getFullYear();
    var dayBirthday = birthDayDate.getDate();
    //first just make the difference between years
    var yearDifference = thisYear - yearBirthday;
    //then check months
    if (thisMonth == monthBirthday){
      //if months are the same then check days
      if (thisDay<dayBirthday){
        //if today day is before birthday day
        //then I have to remove 1 year
        //(no birthday yet)
        yearDifference = yearDifference -1;
      }
      //if not no action because year difference is ok
    }
    else {
      if (thisMonth < monthBirthday) {
        //if actual month is before birthday one
        //then I have to remove 1 year
        yearDifference = yearDifference -1;
      }
      //if not no action because year difference is ok
    }
    return yearDifference;
  }

Answer 18

通过Julian day number进行日期计算。你必须采取两年一月的第一天。然后你将公历日期转换为朱利安日数字，然后你就可以得到差异。

Answer 19

这个帮助你...

     $("[id$=btnSubmit]").click(function () {
        debugger
        var SDate = $("[id$=txtStartDate]").val().split('-');
        var Smonth = SDate[0];
        var Sday = SDate[1];
        var Syear = SDate[2];
        // alert(Syear); alert(Sday); alert(Smonth);
        var EDate = $("[id$=txtEndDate]").val().split('-');
        var Emonth = EDate[0];
        var Eday = EDate[1];
        var Eyear = EDate[2];
        var y = parseInt(Eyear) - parseInt(Syear);
        var m, d;
        if ((parseInt(Emonth) - parseInt(Smonth)) > 0) {
            m = parseInt(Emonth) - parseInt(Smonth);
        }
        else {
            m = parseInt(Emonth) + 12 - parseInt(Smonth);
            y = y - 1;
        }
        if ((parseInt(Eday) - parseInt(Sday)) > 0) {
            d = parseInt(Eday) - parseInt(Sday);
        }
        else {
            d = parseInt(Eday) + 30 - parseInt(Sday);
            m = m - 1;
        }
        // alert(y + " " + m + " " + d);
        $("[id$=lblAge]").text("your age is " + y + "years  " + m + "month  " + d + "days");
        return false;
    });

Answer 20

如果有人需要以浮动格式计算利息年

function floatYearDiff(olddate, newdate) {
  var new_y = newdate.getFullYear();
  var old_y = olddate.getFullYear();
  var diff_y = new_y - old_y;
  var start_year = new Date(olddate);
  var end_year = new Date(olddate);
  start_year.setFullYear(new_y);
  end_year.setFullYear(new_y+1);
  if (start_year > newdate) {
    start_year.setFullYear(new_y-1);
    end_year.setFullYear(new_y);
    diff_y--;
  }
  var diff = diff_y + (newdate - start_year)/(end_year - start_year);
  return diff;
}