is_happening_now.js

function is_happening_now(talk)  {
  // take talk.datetime in ms from epoch
  let talkTime = new Date(talk.datetime).getTime();
  // calculate talkend in ms from epoch
  let talkEnd = talkTime + (talk.duration * 60000);
  // take current epoch time in browser`s timezone
  let now = new Date().getTime();
  // Return boolean true if talk is happening now or false.
  return now > talkTime && now < talkEnd;
}