How to feed the video source based on time range?

Question

Standard HTML5 video element seems to work using byte ranges. The problem is that the server I'm using to serve the video content doesn't support byte ranges. It only supports time ranges (as it's based on ffmpeg).

E.g. I can make a query(in seconds) such http://example.com/myvideo.mkv?range=3.40-49 and it returns video content from 3rd second point 40 ms to 49th second.

Question: is it possible to feed the media source buffer using time ranges? How do I know what time ranges does the media buffer needs and when(e.g. if the client seeks using the progress bar)?

I've checked several players such dash.js but they all assume the server supports byte range so I can't use them.

What I've tried so far: I was thinking to use timestampOffset to feed the array buffer with the correct bytes(time range based) but I don't know when the client seeks and at what position(in seconds). Additionally I think I should fill the range missed but timestampOffset provides only an offset/start point. How do I know the range so that I can avoid overwriting possible already cached/buffered content?

I feel there are a lot of edge cases so I'm wondering if there is already a such player supporting time range instead of byte range. I basically just want to provide a function (videoSourceBuffer, startTime, stopTime) which fills videoSourceBuffer with the video content starting at startTime and stoping at stopTime.

  var mediaSource = new MediaSource();
    mediaSource.addEventListener('sourceopen', function() {
        var sourceBuffer = mediaSource.addSourceBuffer('video/webm; codecs="vorbis,vp8"');
            sourceBuffer.timestampOffset = 0;
            sourceBuffer.appendBuffer(videoBinary);
    });