code: function(db, date, callback) {
  
    // Check cache for service exceptions
    let cacheKey = db.id + "-" + date;
    let cache = cache_serviceExceptionsByDate.get(cacheKey);
    if ( cache !== null ) {
      return callback(null, cache);
    }
  
    // Array of Service Exceptions to return
    let rtn = [];
  
    // Get service exceptions from calendar_dates
    let select = "SELECT service_id, date, exception_type " +
      "FROM gtfs_calendar_dates WHERE date=" + date + ";";
  
    // Query the database
    db.select(select, function(err, results) {
  
      // Database Query Error
      if ( err ) {
        return callback(err);
      }
  
      // Parse each row in the results
      for ( let i = 0; i < results.length; i++ ) {
        let row = results[i];
  
        // Create Service Exception
        let se = new ServiceException(
          row.service_id,
          row.date,
          row.exception_type
        );
  
        // Add Service Exception to return list
        rtn.push(se);
      }
  
      // Add Service Exceptions to cache
      cache_serviceExceptionsByDate.put(cacheKey, rtn);
  
      // Return service exceptions with provided callback
      return callback(null, rtn);
  
    });
  
  }
docs: Get the Service Exceptions in effect on the specified date.  This includes
  Services that are either added or removed on the specified date.
  
  @param {RightTrackDB} db The Right Track Database to query
  @param {int} date The date to query (yyyymmdd)
  @param {function} callback Callback function
  @param {Error} callback.error Database Query Error
  @param {ServiceException[]} callback.services The selected Service Exceptions