// A month has five full weekends when it has 31 days, and the 1st day of the month is a Friday.
// ------------------------------------------------------------
// Month names as a single reusable constant
// ------------------------------------------------------------
const MONTH_NAMES = [
"January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December"
];
// ------------------------------------------------------------
// Function: returns true if a month has 5 full weekends
// ------------------------------------------------------------
function hasFiveFullWeekends(int $year, int $month): bool
{
$firstDay = new DateTimeImmutable("$year-$month-01");
$daysInMonth = (int)$firstDay->format("t");
$weekday = $firstDay->format("N"); // 1=Mon ... 5=Fri ... 7=Sun
return ($daysInMonth === 31 && $weekday == 5); // Friday
}
// ------------------------------------------------------------
// Main program
// ------------------------------------------------------------
$y_value = 2026;
for ($m = 1; $m <= 12; $m++) {
if (hasFiveFullWeekends($y_value, $m)) {
echo MONTH_NAMES[$m - 1] . " $y_value has five full weekends.\n";
}
}
/*
run:
May 2026 has five full weekends.
*/
