Israel declared independence on May 14, 1948, so why is it celebrating its 70th anniversary on April 18?
And why are Palestinians infuriated by the Trump administration's decision to move the American Embassy in Israel from Tel Aviv to Jerusalem on May 14?
The answer lies in two calendars.
Israel marks its public holidays using the Hebrew calendar. May 14, 1948, corresponds to the fifth day of the Jewish month of Iyar in the year 5708.
This spring the fifth day of Iyar — in the year 5778 — lines up with April 18. Israel will celebrate with parties, barbecues, fireworks over the Knesset, Israel's parliament, and an air force flyover along Tel Aviv's shore.
Yet the State Department statement announcing the U.S. Embassy's move to Jerusalem said, "In May, the United States plans to open a new U.S. Embassy in Jerusalem. The opening will coincide with Israel's 70th anniversary."
Is the State Department unaware of the scheduling of Israeli public holidays?
"No question, they didn't consider that," lamented Daniel Shapiro, the former U.S. ambassador to Israel.
Palestinians, however, have noticed.
In May, Palestinians observe Nakba Day, or the "day of catastrophe."
"They deliberately chose a tragic day in Palestinian history, the Nakba, as an act of gratuitous cruelty adding insult to injury," tweeted a livid senior Palestinian official, Hanan Ashrawi.
For Palestinians, who mark their national days according to the Gregorian calendar, May is not a festive month. And to complicate things further, Palestinians observe the day of catastrophe on May 15, the first day of the new state's existence rather than May 14, the day independence was declared.
Palestinian chief negotiator Saeb Erekat issued a statement condemning "the U.S. decision to recognize Jerusalem as Israel's capital and now to move its embassy on the eve of marking 70 years since the Nakba … and provoke the feelings of the Palestinian people, as well as of all Arabs, Muslims and Christians around the globe."
Hamas, the Islamist Palestinian militia that rules Gaza warned that "that this will be the trigger which would detonate the whole area in the face of the Israeli occupation."
Ron Dermer, Israel's ambassador to United States, tried to finesse the awkwardness of the timing of the U.S. Embassy move in a tweet.
Palestinians claim the eastern part of Jerusalem as their capital in a future independent state. Israel, meanwhile, claims Jerusalem as its "eternal and undivided" capital. In December, Trump reversed decades of U.S. and international policy when he announced that he was recognizing Jerusalem as Israel's capital.
On Saturday, Israeli Prime Minister Benjamin Netanyahu released a 14-second statement thanking Trump: "This is a great moment for the state of Israel. President Trump's decision to move the American Embassy to Jerusalem will make our Independence Day celebrations even happier. Thank you, President Trump, for your leadership and your friendship."