我开始在PHP中编写一个函数来查找哪些天是holdiday。然后我注意到这些日子每年都在变化而且不是固定的一天。
因此，我在编写函数来计算这些天时遇到了麻烦，而没有找到确切的日期。
例如：
HOLIDAY 2016 2017
New Years Day January 1 January 1 (Observed Monday, January 2)
Martin Luther King, Jr. Day January 18 January 16
Washington's Birthday February 15 February 20
Good Friday March 25 April 14
Memorial Day May 30 May 29
Independence Day July 4 July 4**
Labor Day September 5 September 4
Thanksgiving Day November 24* November 23*
Christmas December 25 (Observed Monday, December 26) December 25
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