ref: a4fac35c95345ecbf5bd14d19a5e878e14b2b474
dir: /src/libc/time/_daysyear.c/
int _daysmon[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; int _daysyear(int year) { if (year%4 != 0) return 365; if (year%100 == 0 && year%400 != 0) return 365; return 366; }