Do start, stop functions take only seconds?

[scar-2018]

const vCtx = new VideoContext(canvas);
node = vCtx.video(`${videoPath}`);
node.start(0.5);
node.stop(5.5);

I want to start the video from .5s till 5.5s. But it looks like start/stop functions take only seconds. All sample codes also use seconds, not milliseconds.

Is there any way to feed milliseconds in start/stop functions?