Returns the day within which a given timestamp falls in human-friendly terms.

fuzzyDays.js

// Given a timestamp in ms, return the appropriate choice of the following depending on where the timestamp falls:
// X days ago
// yesterday
// today
// tomorrow
// X days from now
function fuzzyDays(timestamp) {
  var fuzz = "today";
  var todayStartMs = Utils.DayStart(new Date()).getTime();
  var dayLengthMs = 24 * 60 * 60 * 1000;
  var daysOff = Math.floor((timestamp - todayStartMs) / dayLengthMs);
  if      (daysOff ==  1) fuzz = "tomorrow";
  else if (daysOff >   1) fuzz = daysOff.toString() + " days from now";
  else if (daysOff == -1) fuzz = "yesterday";
  else if (daysOff <  -1) fuzz = daysOff.toString().substring(1) + " days ago";
  return fuzz;
}