system/Debug/Timer.php
public function getElapsedTime(string $name, int $decimals = 4)
	{
		$name = strtolower($name);

		if (empty($this->timers[$name]))
		{
			return null;
		}

		$timer = $this->timers[$name];

		if (empty($timer['end']))
		{
			$timer['end'] = microtime(true);
		}

		return (float) number_format($timer['end'] - $timer['start'], $decimals);
	}
public function getElapsedTime(string $name, int $decimals = 4)
	{
		$name = strtolower($name);

		if (empty($this->timers[$name]))
		{
			return null;
		}

		$timer = $this->timers[$name];

		if (empty($timer['end']))
		{
			$timer['end'] = microtime(true);
		}

		return (float) number_format($timer['end'] - $timer['start'], $decimals);
	}
Returns the duration of a recorded timer.

@param string  $name     The name of the timer.
@param integer $decimals Number of decimal places.

@return null|float       Returns null if timer exists by that name.
Returns a float representing the number of
seconds elapsed while that timer was running.