php time関数の使い方と分析例

<?php
/**
* Simple function to replicate PHP 5 behaviour
*/
function microtime_float()
{
  list($usec, $sec) = explode(" ", microtime());
  return ((float)$usec + (float)$sec);
}
$time_start = microtime_float();
// Sleep for a while
usleep(100);
$time_end = microtime_float();
$time = $time_end - $time_start;
echo "Did nothing in $time seconds/n";
?>

echo strtotime("+1 day"), "/n";
echo strtotime("+1 week"), "/n";

strtotime("+1 day ".$day);
strtotime("2008-01-31 +1 month");
strtotime($day." +1 day");