3 /* roughly 100x faster than mktime() */
4 datetime_sec
datetime_untai(dt
)
11 year
= dt
->year
+ 1900;
14 if (mon
>= 2) { mon
-= 2; }
15 else { mon
+= 10; --year
; }
17 day
= (dt
->mday
- 1) * 10 + 5 + 306 * mon
;
20 if (day
== 365) { year
-= 3; day
= 1460; }
21 else { day
+= 365 * (year
% 4); }
24 day
+= 1461 * (year
% 25);
27 if (day
== 36524) { year
-= 3; day
= 146096; }
28 else { day
+= 36524 * (year
% 4); }
31 day
+= 146097 * (year
- 5);
34 return ((day
* 24 + dt
->hour
) * 60 + dt
->min
) * 60 + dt
->sec
;