src/Debug/Debug.php
public function timeLog($label = null, $args = null)
    {
        $args = \func_get_args();
        $meta = $this->internal->getMetaVals(
            $args,
            array('channel' => $this->cfg['channel'])
        );
        $microT = 0;
        $ellapsed = 0;
        if (\count($args) === 0) {
            $args[0] = 'time';
            if (!$this->data['timers']['stack']) {
                list($ellapsed, $microT) = $this->data['timers']['labels']['debugInit'];
            } else {
                $microT = \end($this->data['timers']['stack']);
            }
        } elseif (isset($this->data['timers']['labels'][$label])) {
            list($ellapsed, $microT) = $this->data['timers']['labels'][$label];
        } else {
            $args = array('Timer \''.$label.'\' does not exist');
        }
        if ($microT) {
            $args[0] .= ': ';
            $ellapsed += \microtime(true) - $microT;
            $ellapsed = \number_format($ellapsed, 4, '.', '');
            \array_splice($args, 1, 0, $ellapsed.' sec');
        }
        $this->appendLog(
            'timeLog',
            $args,
            $meta
        );
    }
public function timeLog($label = null, $args = null)
    {
        $args = \func_get_args();
        $meta = $this->internal->getMetaVals(
            $args,
            array('channel' => $this->cfg['channel'])
        );
        $microT = 0;
        $ellapsed = 0;
        if (\count($args) === 0) {
            $args[0] = 'time';
            if (!$this->data['timers']['stack']) {
                list($ellapsed, $microT) = $this->data['timers']['labels']['debugInit'];
            } else {
                $microT = \end($this->data['timers']['stack']);
            }
        } elseif (isset($this->data['timers']['labels'][$label])) {
            list($ellapsed, $microT) = $this->data['timers']['labels'][$label];
        } else {
            $args = array('Timer \''.$label.'\' does not exist');
        }
        if ($microT) {
            $args[0] .= ': ';
            $ellapsed += \microtime(true) - $microT;
            $ellapsed = \number_format($ellapsed, 4, '.', '');
            \array_splice($args, 1, 0, $ellapsed.' sec');
        }
        $this->appendLog(
            'timeLog',
            $args,
            $meta
        );
    }
Log the running time without stopping/pausing the timer
also logs additional arguments

Added to web console api in Firefox 62
Added to PHPDebugConsole in v2.3

@param string $label   (optional) unique label
@param mixed  $arg,... (optional) additional values to be logged with time

@return void