(PHP 4, PHP 5, PHP 7, PHP 8)

microtime — Return current Unix timestamp with microseconds

Description

For performance measurements, using hrtime() is recommended.

Parameters

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 number of seconds since the Unix epoch (0:00:00 January 1,1970 GMT), and msec measures microseconds that have elapsed since sec and is also expressed in seconds as a decimal fraction.

If 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.

Examples

<?php
$time_start = microtime(true);
// Sleep for a while
usleep(10_000);
$time_end = microtime(true);
$time = $time_end - $time_start;
print "Did nothing in $time seconds\n";

<?php
// Randomize sleeping time
usleep(random_int(10_000, 1_000_000));
// 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
• hrtime() - Get the system's high resolution time