Hillary Clinton’s presidential campaign is celebrating her victory in the Democratic presidential primary by sending a commemorative refrigerator magnet to supporters who donate $10 or more. However, the date on the magnet is incorrect.

Clinton became the first woman to be the nominee of a major presidential party in an American election on Monday, June 6.

The magnet, which reads “History made,” presents the date of Clinton’s win as “June 7, 2016.” Yet Clinton clinched the delegate majority the day before, when the Associated Press announced that she had passed the threshold, based on its survey of “superdelegates” — party insiders holding a vote at the Democratic National Convention in Philadelphia in July.

The date of the announcement was no small matter. It occurred one day before the historic California primary, and supporters of Sen. Bernie Sanders (I-VT) blamed the Associated Press for suppressing voter turnout by declaring the race over.

As Breitbart News reported:

Many of the people outside Bernie’s [Diner in Los Angeles] felt cheated by the timing of the Associated Press announcement on Monday, announcing that Clinton had clinched the nomination based on the party’s “superdelegates.” “Yesterday, when they were announcing that she already had enough delegates, it was the exact same thing as [George W.] Bush in Florida [in 2000],” a man named Freddie ,who identified himself as a former Hillary supporter, said. “It’s like, dude, you’re playing old politics, why are you doing this?” “I’m not surprised the AP did that last night, but am I upset? Yes I am,” Rick Sanchez told Breitbart News when asked about the AP’s call for Hillary Monday. Referring to the email scandal that has plagued the Clinton campaign, he said: “I hope Bernie won’t drop out tonight, because Hillary still is under investigation by two different government agencies for the same issue.”

One possible explanation for the error on the magnet is that the Clinton campaign did not want to rub salt in the wounds of Sanders fans. Clinton needs to unify her party after a contentious primary battle to face Republican Donald Trump this fall.

The Clinton campaign also evidently declined to use the feminist-friendly term “herstory” in favor of the traditional “history.”

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new e-book, Leadership Secrets of the Kings and Prophets: What the Bible’s Struggles Teach Us About Today, is on sale through Amazon Kindle Direct. Follow him on Twitter at @joelpollak.