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Date/Time Functions
PHP Manual

# microtime

(PHP 4, PHP 5)

microtime — Return current Unix timestamp with microseconds

### Description

mixed microtime ([ bool `$get_as_float` = false ] )

microtime() returns the current Unix timestamp with microseconds. This function is only available on operating systems that support the gettimeofday() system call.

### Parameters

`get_as_float`

  If used and set to `TRUE`, microtime() will return a float instead of a string, as described in the return values section below.

### Return Values

By default, microtime() returns a string in the form "msec sec", where sec is the current time measured in the number of seconds since the Unix epoch (0:00:00 January 1, 1970 GMT), and msec is the number of microseconds that have elapsed since sec expressed in seconds.

If `get_as_float` is set to `TRUE`, then microtime() returns a float, which represents the current time in seconds since the Unix epoch accurate to the nearest microsecond.

### Changelog

Version | Description
--- | ---
5.0.0 | The `get_as_float` parameter was added.

### Examples

Example #1 Timing script execution with microtime()

`<?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";
?>`

Example #2 Timing script execution in PHP 5

`<?php
$time_start = microtime(true);
// Sleep for a while
usleep(100);
$time_end = microtime(true);
$time = $time_end - $time_start;
echo "Did nothing in $time seconds\n";
?>`

Example #3 microtime() and REQUEST_TIME_FLOAT (as of PHP 5.4.0)

`<?php
// Randomize sleeping time
usleep(mt_rand(100, 10000));
// As of PHP 5.4.0, REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
// It contains the timestamp of the start of the request with microsecond precision.
$time = microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];
echo "Did nothing in $time seconds\n";
?>`

### See Also

- time() - Return current Unix timestamp

localtime
mktime
Date/Time Functions
PHP Manual