PHP get next month first day and remaining days to this date

Below method is tweaked to take account of December. This method is leap-year safe. The day count must include floor().

$curMonth = date('n');
$curYear  = date('Y');
if ($curMonth == 12)
	$firstDayNextMonth = mktime(0, 0, 0, 0, 0, $curYear+1);
else
	$firstDayNextMonth = mktime(0, 0, 0, $curMonth+1, 1);

echo floor($daysTilNextMonth = ($firstDayNextMonth - time()) / (24 * 3600));

From above mktime calculation, not only get the number of days, we can count the hours and minutes till next month first day. Example:

$day_count = floor(($firstDayNextMonth - time()) / (24 * 3600));
$hour_count = floor(($firstDayNextMonth - time()) / (3600));
$minute_count = (($firstDayNextMonth - time()) / (60));

By Keenlio, February 20, 2014