Am I stuck in Schiphol?

Yeah, you're probably stuck. Schiphol is big, so you need to allow time to get through the airport going and returning, plus security checks. And you'll have to be at the gate to board at least 30 minutes before leaving. There are frequent trains to Amsterdam, the ride is about 15 minutes, but you have to buy tickets first. It's been awhile since I visited but I didn't find machines that took cash and there always seem to be lines at the ticket agent windows. Hardly seems worth it to spend an hour in Amsterdam and be worried that you might run into a snag on returning - train delay, long security line, remote gate.

Just enjoy the airport. There are museum-type displays and plenty of places to window shop and to have a drink or a meal.

As Chani said, lots to do at the airport. Schiphol is my favorite airport, lots of ways to pass the time.

You can do your currency exchange during the long wait. Walk as much as you can after the trans-Atlantic flight. Near the museum there is a piano anyone can play. Use the WiFi too. If you have a long delay on the return trip, keep alert to the extra time for boarding. Delta will want you in the departure area well before the stated time. The airline often conducts an extra security check, including hand baggage and maybe even an interview, and wants you not just in the lounge but in your airplane seat half an hour before departure. The airport is known for its duty-free shopping, on the international flight west, but the savings are not as automatic as a couple of decades ago, especially because of currency fluctuations. http://www.schiphol.nl/Travellers/FoodRelax.htm

I have the same likely layover coming up next year, and plan to stay in the airport. There's plenty to do - even the airport's website has a section called "enjoy your transfer" with plenty of ideas. I believe the airport is undergoing some construction, but last time I flew through there was a small outpost of the Rijksmuseum (it may or may not be open now) and also a library. I believe there's also an outdoor area you can get some fresh air. As mentioned above, make sure to get to your gate at least 30 minutes before your flight, some gates have an additional security scan.

Thanks for the info. Stuck.
I haven't been in Schiphol since coming through in the 1970's, though it's about my fortieth trans-Atlantic. Haven't been to Amsterdam since I brought my French MIL to see the then newly opened Van Gogh Museum in the 1980's. Because Delta initiated the change, I'll see if they can give us a couple day's stopover or an earlier flight on to Bordeaux. At least I don't have to change at CDG.

I was stuck there that long. Loved it. Got a massage in the meantime, visited the little Rijksmuseum (the airport version), ate something delicious and had a really good time wandering in the shops (there were a lot of flower bulb places which I haven't seen at other airports, obviously). It's my second-favorite airport after Munich.

"I just got back from Amsterdam and the time from entering the airport to sitting at my gate took 2 hours and 25 min."

Makes sense. Good info. Looks like there may not even be time for that massage that sounds so tempting! Will keep the flights as is or try for a stopover.
Thank you everyone.

Hello Bets , We were at Schipol for five hours in September waiting on the transfer to St. Petersburg . Not bad at all - some coffee and a bite , and a pleasant place to land ( no pun intended ) for a break from NY to Amsterdam . Walked around , and stretched a bit , and was able to finish the new biography of Joseph Mitchell ( by Thomas Kunkel ) in the waiting area . The time actually passed more easily than we expected .

I don't know if this area is still there or not with the construction going on but 2 years ago up on the Mezzanine area there was a section that had lounge chairs. You just have to make sure not everyone goes to sleep!