code: function get_timeout_delay(date, settings)
      {
          var now = get_now();
          var diff = ((now.getTime() - date.getTime()) / 1000);
          var diff_abs = Math.abs(diff);
          
          if(isNaN(diff))
              return;
          
          var last_limit = 0;
          for(var i in settings.units)
          {
              var unit = settings.units[i];
              
              // Skip this unit if it's for past dates only and this is a future
              // date, or if it's for future dates only and this is a past date.
              if((unit.past_only && diff < 0) || (unit.future_only && diff > 0))
                  continue;
              
              if(diff_abs < unit.limit)
              {
                  // @todo: check edge cases (diff == 0)
                  if(isNaN(unit.in_seconds))
                  {
                      // This is not a real unit of time, so only update once we
                      // pass the limit of this unit.
                      if(diff < 0)
                          return (last_limit - diff_abs) * 1000 + 100;
                      else
                          return (unit.limit - diff_abs) * 1000 + 100;
                  }
                  else
                  {
                      // Real unit of time - update every tick of this time unit.
                      if(diff < 0)
                          return (diff_abs % unit.in_seconds) * 1000 + 100
                      else
                          return (unit.in_seconds - (diff_abs % unit.in_seconds)) *
                              1000 + 100
                  }
              }
              last_limit = unit.limit;
          }
          
          // Date is out of range of all units' limits. If this is a future date,
          // update once the date comes in range of a future unit.
          if(diff < 0)
          {
              for(var i = settings.units.length - 1; i >= 0; i--)
              {
                  var unit = settings.units[i];
                  
                  if(unit.past_only)
                      continue;
                  
                  return (unit.limit - diff_abs) * 1000 + 100
              }
          }
      }
docs: Returns how long (in milliseconds) the timout until the next update for the given date should be.