将公历日期转换为回历日期

Question

如何使用 JavaScript 将公历日期转换为伊斯兰回历日期？

原文由 FuNk 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

function gmod(n,m){
return ((n%m)+m)%m;
}

function kuwaiticalendar(adjust){
var today = new Date();
if(adjust) {
    adjustmili = 1000*60*60*24*adjust;
    todaymili = today.getTime()+adjustmili;
    today = new Date(todaymili);
}
day = today.getDate();
month = today.getMonth();
year = today.getFullYear();
m = month+1;
y = year;
if(m<3) {
    y -= 1;
    m += 12;
}

a = Math.floor(y/100.);
b = 2-a+Math.floor(a/4.);
if(y<1583) b = 0;
if(y==1582) {
    if(m>10)  b = -10;
    if(m==10) {
        b = 0;
        if(day>4) b = -10;
    }
}

jd = Math.floor(365.25*(y+4716))+Math.floor(30.6001*(m+1))+day+b-1524;

b = 0;
if(jd>2299160){
    a = Math.floor((jd-1867216.25)/36524.25);
    b = 1+a-Math.floor(a/4.);
}
bb = jd+b+1524;
cc = Math.floor((bb-122.1)/365.25);
dd = Math.floor(365.25*cc);
ee = Math.floor((bb-dd)/30.6001);
day =(bb-dd)-Math.floor(30.6001*ee);
month = ee-1;
if(ee>13) {
    cc += 1;
    month = ee-13;
}
year = cc-4716;

wd = gmod(jd+1,7)+1;

iyear = 10631./30.;
epochastro = 1948084;
epochcivil = 1948085;

shift1 = 8.01/60.;

z = jd-epochastro;
cyc = Math.floor(z/10631.);
z = z-10631*cyc;
j = Math.floor((z-shift1)/iyear);
iy = 30*cyc+j;
z = z-Math.floor(j*iyear+shift1);
im = Math.floor((z+28.5001)/29.5);
if(im==13) im = 12;
id = z-Math.floor(29.5001*im-29);

var myRes = new Array(8);

myRes[0] = day; //calculated day (CE)
myRes[1] = month-1; //calculated month (CE)
myRes[2] = year; //calculated year (CE)
myRes[3] = jd-1; //julian day number
myRes[4] = wd-1; //weekday number
myRes[5] = id; //islamic date
myRes[6] = im-1; //islamic month
myRes[7] = iy; //islamic year

return myRes;
}
function writeIslamicDate(adjustment) {
var wdNames = new Array("Ahad","Ithnin","Thulatha","Arbaa","Khams","Jumuah","Sabt");
var iMonthNames = new Array("Muharram","Safar","Rabi'ul Awwal","Rabi'ul Akhir",
"Jumadal Ula","Jumadal Akhira","Rajab","Sha'ban",
"Ramadan","Shawwal","Dhul Qa'ada","Dhul Hijja");
var iDate = kuwaiticalendar(adjustment);
var outputIslamicDate = wdNames[iDate[4]] + ", "
+ iDate[5] + " " + iMonthNames[iDate[6]] + " " + iDate[7] + " AH";
return outputIslamicDate;
}

这会将 当前 计算机日期转换为回历。稍作修改，您就可以实现此代码段将任何日期更改为伊斯兰日期

document.write(writeIslamicDate(1));

取自 本站

原文由 Lixas 发布，翻译遵循 CC BY-SA 2.5 许可协议

Answer 2

如果您只需要从公历日期（Miladi 日期）转换的回历年，您可以简单地用 javascript 编写此等式：

 var GregorianYear = (new Date()).getFullYear();
var HijriYear = Math.round((GregorianYear - 622) * (33 / 32));

你可以在母版页的页脚中使用这个简单的等式，比如

<script type="text/javascript">document.write((new Date()).getFullYear())</script> م - <script type="text/javascript">var y = (new Date()).getFullYear();var h = Math.round((y - 622) * (33 / 32));document.write(h)</script> هـ

你会得到： كل الحقوق محفوط لـ … © 2014 م - 1435 هـ

您还可以使用嵌入在 asp 页面中的 C# 作为：

 <%= DateTime.Now.Year %> - <%=  Math.Round((DateTime.Now.Year - 622) * 1.03125) %>

回归时间：2014 - 1436

最后，如果您需要转换为 UmAlQura 日期，只需尝试这行代码：

 let _date = new Date('7/10/2019').toLocaleDateString('ar-SA').format('DD/MM/YYYY');

console.log(_date);

将返回：٧ /١١ /١٤٤٠ هـ

更新（2021-10-11）：如果您需要更精确的方程式，则必须通过以下公式知道太阳年的当前日期：

 var now = new Date();
var start = new Date(now.getFullYear(), 0, 0);
var diff = now - start;
var oneDay = 1000 * 60 * 60 * 24;
var dayOfYear = Math.floor(diff / oneDay);

然后你可以通过这个公式得到回历年：

 HijriYear = ((GregorianYear-621.5643)*365.24225 + dayOfYear) / 354.36707

在哪里 ：

365.24225 是太阳年的天数。

354.36707 是农历年的天数。

621.5643 是 Hijra 的确切公历日期（Hijri 日期的开始日期）

回历年 = ((2021-621.5643)*365.24225 + 284) / 354.36707 = 1,443.18444

因此，通过使用 Math.floor(HijriYear) 函数，当前回历年是 1443 年。

您也可以使用分数：

 var hijriDayOfYear  = (HijriYear - Math.floor(HijriYear)) * 354.36707

0.18444 乘以 354.36707 得到回历中的天数：

0.18444 * 354.36707 = 65.3 ：当前回历年的天数

Math.ceil(hijriDayOfYear / 29.530589) = 3 当前回历月数

Math.floor(hijriDayOfYear % 29.530589) = 6 ± 1 回历月的天数

最后总结一下之前的所有内容，只需使用以下 JS 代码：

 var now = new Date()
var dayOfYear = Math.floor((new Date() - new Date(now.getFullYear(), 0, 0)) / (1000 * 60 * 60 * 24))
var hijriDate = ((now.getFullYear()-621.5643)*365.24225 + dayOfYear) / 354.36707
var hijriYear = Math.floor(hijriDate)
var hijriMonth = Math.ceil((hijriDate - Math.floor(hijriDate)) * 354.36707 / 29.530589)
var hijriDay = Math.floor((hijriDate - Math.floor(hijriDate)) * 354.36707 % 29.530589)

console.log(`${hijriYear}/${hijriMonth}/${hijriDay}`)

控制台输出示例：1443/3/6

将日期时间转换为回历日期的通用 JavaScript 函数：

 function GetHijriDate(dateTime) {
    var dayOfYear = Math.floor((dateTime - new Date(dateTime.getFullYear(), 0, 0)) / (1000 * 60 * 60 * 24))
    var hijriDate = ((dateTime.getFullYear() - 621.5643) * 365.24225 + dayOfYear) / 354.36707
    var hijriYear = Math.floor(hijriDate)
    var hijriMonth = Math.ceil((hijriDate - Math.floor(hijriDate)) * 354.36707 / 29.530589)
    var hijriDay = Math.floor((hijriDate - Math.floor(hijriDate)) * 354.36707 % 29.530589)
    return [hijriYear, hijriMonth , hijriDay]
}

在 C# 中：

     /// <summary>
    /// Gets the hijri date.
    /// </summary>
    /// <param name="date">The date.</param>
    /// <returns></returns>
    public static int[] GetHijriDate(DateTime date)
    {
        var yearOfHijra = 621.5643f;
        var daysInSolarYear = 365.24225f;
        var daysInLunarYear = 354.36707f;
        var daysInLunarMonth = 29.53058f;

        var hijriDate = ((date.Year - yearOfHijra) * daysInSolarYear  + date.DayOfYear) / daysInLunarYear;
        var hijriYear = (int)Math.Floor(hijriDate);
        var hijriMonth = (int)Math.Ceiling((hijriDate - Math.Floor(hijriDate)) * daysInLunarYear / daysInLunarMonth);
        var hijriDay = (int)Math.Floor((hijriDate - Math.Floor(hijriDate)) * daysInLunarYear % daysInLunarMonth);

        int[] hijriDateRes = new int[3];
        hijriDateRes[0] = hijriYear;
        hijriDateRes[1] = hijriMonth;
        hijriDateRes[2] = hijriDay;

        return hijriDateRes;
    }

或者简单地：

 console.log(new Date().toLocaleDateString('ar-SA'))

‘٥ /٣ /١٤٤٣ هـ’

原文由 Zakaria 发布，翻译遵循 CC BY-SA 4.0 许可协议