I bought 4 tickets by mistake for Anne Frank House

As you've phrased this just right to allow this post to stay, note that we can't allow transactions via this forum for reasons of liability, safety, etc. We're just not set up for that. You'll want to use a site that is set up to handle transactions such as StubHub, Craigslist, or eBay.

It's also worth noting (without casting judgment on the OP, who has a perfectly understandable reaction to buying tickets for the wrong day) that the Anne Frank House does not permit the re-sale of tickets without its permission.

In its Terms and Conditions it states:

Article 2.4

The resale of entrance tickets is not permitted without the prior permission of the Anne Frank House. The potential visitor may be denied access to the museum complex if it turns out that the entrance ticket, discount card or voucher has not been directly acquired from the Anne Frank House or an organisation authorised for this purpose by the Anne Frank House.

If you are going to be in Amsterdam before 12/21, maybe you could return them to the Anne Frank House and get a refund? I'd bet they could sell them.

If not, you might be able to contact them online and work something out.

I have bought tickets elsewhere for the wrong date, and after some groveling and humbly beseeching, I was able to exchange them.

You have nothing to lose by asking for a refund or exchange. They have no trouble selling tickets.

Just give them away as a donation maybe you can write it off your taxes
https://www.annefrank.org/en/about-us/support-us/

It will not be a tax write off because donations to a foreign charity are not tax deductible. Yes, I have researched it in preparing my taxes.

If the Anne Frank house will not permit you to exchange them, just give them away as a charitable act so they won't be left unused. Fortunately they are not expensive tickets.

Just contact them, maybe they can exchange them for another date? they do not give refunds. Good luck!