microtime

Return current Unix timestamp with microseconds

Description

stringfloat microtime(bool $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.

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

Example #1 Timing script execution

<?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 #2 microtime and REQUEST_TIME_FLOAT

<?php
// Randomize sleeping time
usleep(mt_rand(100, 10000));

// 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
  • hrtime