Compile-time date parser, converts `__DATE__` to ints

date_parse.c

#include <stdio.h>

#define pp_current_build_year (((__DATE__[7] - '0') * 1000) + ((__DATE__[8] - '0') * 100) + ((__DATE__[9] - '0') * 10) + (__DATE__[10] - '0'))
#define pp_current_build_day ((((__DATE__[4] - ' ') % 16) * 10) + (__DATE__[5] - '0'))
#define MONTH_CMP(b) ((__DATE__[0] == (b)[0]) && (__DATE__[1] == (b)[1]) && (__DATE__[2] == (b)[2]))
#define pp_current_build_month (  \
	(MONTH_CMP("Jan") * ( 1)) + \
	(MONTH_CMP("Feb") * ( 2)) + \
	(MONTH_CMP("Mar") * ( 3)) + \
	(MONTH_CMP("Apr") * ( 4)) + \
	(MONTH_CMP("May") * ( 5)) + \
	(MONTH_CMP("Jun") * ( 6)) + \
	(MONTH_CMP("Jul") * ( 7)) + \
	(MONTH_CMP("Aug") * ( 8)) + \
	(MONTH_CMP("Sep") * ( 9)) + \
	(MONTH_CMP("Oct") * (10)) + \
	(MONTH_CMP("Nov") * (11)) + \
	(MONTH_CMP("Dec") * (12))   \
)

#define pp_current_build_hour (((__TIME__[0] - '0') * 10) + (__TIME__[1] - '0'))
#define pp_current_build_min (((__TIME__[3] - '0') * 10) + (__TIME__[4] - '0'))
#define pp_current_build_sec (((__TIME__[6] - '0') * 10) + (__TIME__[7] - '0'))
#define pp_current_build_year_is_leap_year_p ((!(pp_current_build_year % 4)) | ((!(pp_current_build_year % 400)) + (!(pp_current_build_year % 100)) == 2))
#define pp_current_build_day_of_year ((pp_current_build_day) + (pp_current_build_year_is_leap_year_p?((int[]){0, 31, 60, 90, 121, 151, 182, 213, 244, 274, 304, 335}[pp_current_build_month - 1]):((int[]){0, 31, 59, 89, 120, 150, 181, 212, 243, 273, 303, 334}[pp_current_build_month - 1])))
#define pp_current_build_zodiac (pp_current_build_day <= ((const int[12]){ \
		20, 18, 20, 19, 20, 21, 22, 22, 22, 23, 22, 21 \
	})[pp_current_build_month - 1] ? (pp_current_build_month \
	- 1) % 12 : pp_current_build_month % 12)
#define pp_current_build_moon_phase (((((((pp_current_build_day_of_year - (int[19]){6, 24, 13, 2, 21, 10, 29, 18, 8, 26, 15, 4, 23, 11, 1, 20, 9, 27, 16}[pp_current_build_year%19])*100) % 2953)+50)/100) / (2953/800)) % 8)

int main(void){
	const char *signs[12] = {
		"Capricorn", "Aquarius", "Pisces",
		"Aries", "Taurus", "Gemini",
		"Cancer", "Leo", "Virgo",
		"Libra", "Scorpio", "Sagittarius"
	};
	const char *moon_phases[8] = {
		"New", "Waxing crescent",
		"First quarter", "Waxing gibbous",
		"Full", "Waning gibbous",
		"Last quarter", "Waning crescent"
	};

	printf("%d\n", pp_current_build_year);
	printf("%d\n", pp_current_build_month);
	printf("%d\n", pp_current_build_day);
	printf("%d\n", pp_current_build_hour);
	printf("%d\n", pp_current_build_min);
	printf("%d\n", pp_current_build_sec);
	printf("This is %sa leap year\n", pp_current_build_year_is_leap_year_p?"":"not ");
	printf("Day of year: %d\n", pp_current_build_day_of_year);
	puts(signs[pp_current_build_zodiac]);
	puts(moon_phases[pp_current_build_moon_phase]);
	printf("%.2d-%.2d-%.2d %.2d:%.2d:%.2d UTC\n", pp_current_build_year, pp_current_build_month, pp_current_build_day, pp_current_build_hour, pp_current_build_min, pp_current_build_sec);
}