Hello !
Sometimes we need to obtain the PHP execution time
I make an example
 
<?php
//Get microtime function
//TRUE meaning refers to the return [floating-point numbers microtime]
//If the default display [decimal microtime] + [sec]
$startTime = microtime(TRUE);

//sleep 2 second
sleep(2);

//end time
$endTime = microtime(TRUE);

//show Time
echo $endTime - $startTime.'秒';
?>
 
So we can know
Use microtime() and time() is the same content
The only difference is microtime() have microtime float number
so...
microtime usually use the TRUE setup to easy Calculate
Hopefully this for those who need help
Thanksgiving!