//
// sipage.js
//
// Calculate the age of SIP and display it on the screen
// SIP Birth date: Feb 22, 1996 (Day of year: 53)
//

// Define constants
var birth_year = 1996;
var birth_day = 53;

function IsLeapYear(year)
{
    if (year < 1800)
    {
        return (year & 3) ? 0 : 1;
    }
    else
    {
        return (year & 3) ? 0 :
            ((!(year % 100) && (year % 400)) ? 0 : 1);
    }
}

// The following thanks to: http://www.merlyn.demon.co.uk/js-date0.htm#DoY
function DayOfYear(D)
{
    var t = +D,
    d = new Date(t)
    d.setUTCMonth(0, 0) // Previous Dec 31, same time
    return Math.round((t-d)/864e5) // Round allows Summer Time
}

var years_old;
var days_old;
var today = new Date();
var year = today.getUTCFullYear();
var mon = today.getUTCMonth() + 1;
var yday = DayOfYear(today);

if (yday >= birth_day)
{
    years_old = year - birth_year;
    days_old = yday - birth_day;
}
else
{
    years_old = year - birth_year - 1;
    days_old = 365 - birth_day + yday;
    if (IsLeapYear(year-1))
    {
        days_old++;
    }
}

document.write(years_old + " years, " + days_old + " days old");