ref: 2e7e4ca6b9def1b7bae6b93285f6431039f9656a dir: /src/libc/time/_newyear.c/
/* * Happy New Year!!!! */ int _newyear(int year) { int day; year += 1900 - 1; day = 1 + year + year/4; day -= year/100; day += year/400; return day % 7; }