code: function _buildEffectiveServiceIDString(db, date, callback) {
  
    // Query the Calendar for effective services
    CalendarTable.getServicesEffective(db, date, function(err, services) {
  
      // Database Query Error
      if ( err ) {
        return callback(err);
      }
  
      // Build Service ID String
      let serviceIds = [];
      for ( let i = 0; i < services.length; i++ ) {
        serviceIds.push(services[i].id);
      }
      let serviceIdString = "('" + serviceIds.join("', '") + "')";
  
      // Return Service ID String
      return callback(null, serviceIdString);
  
    });
  
  }
docs: Build the Effective Service ID String for SELECT query
  @param {RightTrackDB} db The Right Track DB to query
  @param {int} date Date Integer (yyyymmdd)
  @param {function} callback Callback function(err, serviceIdString)
  @private