ÿþvar PERSIAN_EPOCH = 1948320.5;

var PERSIAN_WEEKDAYS = new Array("J© 4F(G", "/H 4F(G","3G 4F(G", "†G'1 4F(G","~F, 4F(G", ",E9G", "4F(G");

	var PERSIAN_MONTHS = new Array("A1H1/JF","'1/J(G4*",".1/'/","*J1","E1/'/","4G1JH1","EG1",""('F",""01","/J","(GEF","'3AF/");



//  LEAP_PERSIAN  --  Is a given year a leap year in the Persian calendar ?

function leap_persian(year)

{

    return ((((((year - ((year > 0) ? 474 : 473)) % 2820) + 474) + 38) * 682) % 2816) < 682;

}

	

//  PERSIAN_TO_JD  --  Determine Julian day from Persian date

function persian_to_jd(year, month, day)

{

    var epbase, epyear;



    epbase = year - ((year >= 0) ? 474 : 473);

    epyear = 474 + mod(epbase, 2820);



    return day +

            ((month <= 7) ?

                ((month - 1) * 31) :

                (((month - 1) * 30) + 6)

            ) +

            Math.floor(((epyear * 682) - 110) / 2816) +

            (epyear - 1) * 365 +

            Math.floor(epbase / 2820) * 1029983 +

            (PERSIAN_EPOCH - 1);

}



//  JD_TO_PERSIAN  --  Calculate Persian date from Julian day

function jd_to_persian(jd)

{

    var year, month, day, depoch, cycle, cyear, ycycle,

        aux1, aux2, yday;





    jd = Math.floor(jd) + 0.5;



    depoch = jd - persian_to_jd(475, 1, 1);

    cycle = Math.floor(depoch / 1029983);

    cyear = mod(depoch, 1029983);

    if (cyear == 1029982) {

        ycycle = 2820;

    } else {

        aux1 = Math.floor(cyear / 366);

        aux2 = mod(cyear, 366);

        ycycle = Math.floor(((2134 * aux1) + (2816 * aux2) + 2815) / 1028522) +

                    aux1 + 1;

    }

    year = ycycle + (2820 * cycle) + 474;

    if (year <= 0) {

        year--;

    }

    yday = (jd - persian_to_jd(year, 1, 1)) + 1;

    month = (yday <= 186) ? Math.ceil(yday / 31) : Math.ceil((yday - 6) / 30);

    day = (jd - persian_to_jd(year, month, 1)) + 1;

    return new Array(year, month, day);

}



//  LEAP_GREGORIAN  --  Is a given year in the Gregorian calendar a leap year ?

function leap_gregorian(year)

{

    return ((year % 4) == 0) &&

            (!(((year % 100) == 0) && ((year % 400) != 0)));

}



//  GREGORIAN_TO_JD  --  Determine Julian day number from Gregorian calendar date

var GREGORIAN_EPOCH = 1721425.5;



function gregorian_to_jd(year, month, day)

{

    return (GREGORIAN_EPOCH - 1) +

           (365 * (year - 1)) +

           Math.floor((year - 1) / 4) +

           (-Math.floor((year - 1) / 100)) +

           Math.floor((year - 1) / 400) +

           Math.floor((((367 * month) - 362) / 12) +

           ((month <= 2) ? 0 :

                               (leap_gregorian(year) ? -1 : -2)

           ) +

           day);

}



function ShowPersianDate()

{

    var j, year, mon, mday, weekday ;



    var today = new Date();



    year = today.getYear();

    if (year  < 1000)

        year  += 1900;



    mon = today.getMonth();

    mday = today.getDate();



    j = gregorian_to_jd(year, mon + 1, mday);

    weekday = jwday(j);

    perscal = jd_to_persian(j);

    //document.getElementById("CalendarTD").innerHTML = PERSIAN_WEEKDAYS[weekday] + "  " + perscal[2] + "  " + PERSIAN_MONTHS[perscal[1]-1] + "  " + perscal[0];

    document.getElementById("CalendarTD").innerHTML = PERSIAN_WEEKDAYS[weekday] + "  " + perscal[2] + "  " + PERSIAN_MONTHS[perscal[1]-1];

}



function jwday(j)

{

    return mod(Math.floor((j + 1.5)), 7);

}



function mod(a, b)

{

    return a - (b * Math.floor(a / b));

}