Question

The API documentation does not contain an obvious way to trigger a javascript event when a YouTube video reaches a certain time stamp. Do you know any workaround?

Answer 1

You can create a timer which check at second whether video has reached certain timestamp.
To restrict unnecessary function calls, start time only when it reaches your set time

var timeout = setTimeout(function(){
  var interval = setInterval(function(){
    if(player.getCurrentTime() === <you_set_time>){
        clearInterval(interval);
        // Your logic
    }

  },1000);
},<your_set_time_in_millisecs>);