Expiring data and a possible way to handle it.

expirationDateExample.js

/** A way to stay aware of when any code used in this script will expire.
 * For example, if dataObj1 is only valid till June 1, 2017, then
 * this script should only be valid till then. After that the code
 * should be changed to point to a new, valid, object.
 * @exports {Date} expirationDate
 */
var expirationDate = new Date( 2018, 12, 31 );

// or it could calculate the expiration date based on all the objects it's pulling in
var calcExpirationDate = function() {
  var date = new Date( 2018, 12, 31 );
  for ( allImportedObjects ) {
    if ( oneObj.expirationDate.getMilliseconds() < date.getMilliseconds() ) {
      date = oneObj.expirationDate;
    }
  }
  return date;
};  // End calcExpirationDate()
expirationDate = calcExpirationDate();