PHP

<?php
date_default_timezone_set("Asia/Kolkata");
echo "d-m-Y        : " . date("d-m-Y") . "<br>";
echo "D, jS F Y    : " . date("D, jS F Y") . "<br>";
echo "l            : " . date("l") . "<br>";
echo "h:i:s A      : " . date("h:i:s A") . "<br>";
echo "H:i (24 hr)  : " . date("H:i") . "<br>";
echo "Day of year z: " . date("z") . ", week W: " . date("W") . "<br>";
echo "Days in month: " . date("t") . ", leap year: " . (date("L") ? "yes" : "no") . "<br>";
echo "Time zone    : " . date("T P e") . "<br>";
echo "ISO 8601 (c) : " . date("c") . "<br>";
echo "RFC 2822 (r) : " . date("r") . "<br>";
echo "Escaped text : " . date("\T\o\d\a\y \i\s l");
?>

<?php
date_default_timezone_set("Asia/Kolkata");
$ts = mktime(0, 0, 0, 8, 15, 1947);
echo "15 Aug 1947 was a " . date("l", $ts) . "<br>";
echo "Timestamp now: " . time() . "<br>";
echo "checkdate(2, 29, 2028): " . (checkdate(2, 29, 2028) ? "valid" : "invalid") . "<br>";
echo "checkdate(2, 29, 2027): " . (checkdate(2, 29, 2027) ? "valid" : "invalid") . "<br>";
$d = getdate(mktime(10, 30, 0, 1, 26, 2027));
echo "getdate: {$d['weekday']}, {$d['mday']} {$d['month']} {$d['year']} {$d['hours']}:{$d['minutes']}<br>";
echo "idate('Y'): " . idate('Y') . "<br>";
echo "gmdate('H:i') (UTC): " . gmdate("H:i") . ", local: " . date("H:i");
?>

<?php
date_default_timezone_set("Asia/Kolkata");
$base = mktime(0, 0, 0, 10, 22, 2026);        // a fixed base date: 22 Oct 2026
foreach (["tomorrow", "+1 week", "next monday", "last day of this month",
          "+3 months 2 days", "first sunday of november 2026"] as $text) {
    echo str_pad($text, 30) . " → " . date("D d-m-Y", strtotime($text, $base)) . "<br>";
}
echo "strtotime('2026-12-25 10:00') = " . strtotime("2026-12-25 10:00");
?>

<?php
date_default_timezone_set("Asia/Kolkata");
$dob = new DateTime("2001-05-14");
$today = new DateTime("2026-10-22");
$age = $dob->diff($today);
echo "Age: {$age->y} years, {$age->m} months, {$age->d} days<br>";
echo "Total days: " . $age->days . "<br>";

$due = new DateTime("2026-10-22");
$due->modify("+45 days");
echo "Fee due on: " . $due->format("d M Y (l)") . "<br>";

$interval = new DateInterval("P1M");         // period of 1 month
$period = new DatePeriod(new DateTime("2026-01-10"), $interval, 3);
foreach ($period as $p) {
    echo "Installment: " . $p->format("d-m-Y") . "<br>";
}
$ny = new DateTime("2026-10-22 10:00", new DateTimeZone("Asia/Kolkata"));
$ny->setTimezone(new DateTimeZone("America/New_York"));
echo "10:00 in Bhopal is " . $ny->format("H:i T") . " in New York";
?>

<?php
date_default_timezone_set("Asia/Kolkata");
echo "Days in Feb 2028: " . cal_days_in_month(CAL_GREGORIAN, 2, 2028) . "<br>";
$jd = gregoriantojd(10, 22, 2026);
echo "Julian Day Count of 22-10-2026: $jd<br>";
echo "Day of week: " . jddayofweek($jd, 1) . ", month: " . jdmonthname($jd, 1) . "<br>";
echo "Back to Gregorian: " . jdtogregorian($jd) . "<br>";
echo "Same day in the Julian calendar: " . jdtojulian($jd) . "<br>";
echo "Easter 2027: " . date("d M Y", easter_date(2027)) . " (" . easter_days(2027) . " days after 21 March)<br>";
$info = cal_from_jd($jd, CAL_GREGORIAN);
echo "cal_from_jd: {$info['dayname']}, {$info['day']} {$info['monthname']} {$info['year']}";
?>