Forget Sinister the Indian or windmill sails on the city seal: What has historians in a tizzy the seal's date of 1625. They tell the NY Times the date has "hardly any historical significance."
The Times explains that in 1974, the City Council wanted to diminish the fact British settlers first came to the land that would be the Big Apple. As for what date a revised seal should show, there are different opinions.
Manhattan borough historian Michael Miscino said, "It is simply wrong. The first founding settlers of New York City landed here in 1624.” Charles T. Gehring adds, “If you want to talk about New York City and not Manhattan, then 1624 would be a good date. If you want to put the actual date when it was purchased, when Peter Minuit made the deal, that was 1626.” And Kenneth T. Jackson thinks 1624 is the correct date to use.
On the other side, authors Russell Shorto and Edwin Burrows both think 1653--when New Amsterdam was formally chartered--would be better. Interesting, in the Green Book's Chronology of Important New York City Dates, the important event that occurred in 1653 was how the city's first tavern became the first city hall! (Per Green Book, in 1625, "Town of Nieuw Amsterdam becomes seat of government for Nieuw Netherlands.")