1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
#include <time.h>
// from musl@1cc81f5cb, slightly tweaked
static long long
__year_to_secs(long long year, int *is_leap)
{
if (year-2ULL <= 136) {
int y = year;
int leaps = (y-68)>>2;
if (!((y-68)&3)) {
leaps--;
if (is_leap) *is_leap = 1;
} else if (is_leap) *is_leap = 0;
return 31536000*(y-70) + 86400*leaps;
}
int cycles, centuries, leaps, rem;
cycles = (year-100) / 400;
rem = (year-100) % 400;
if (rem < 0) {
cycles--;
rem += 400;
}
if (!rem) {
*is_leap = 1;
centuries = 0;
leaps = 0;
} else {
if (rem >= 200) {
if (rem >= 300) centuries = 3, rem -= 300;
else centuries = 2, rem -= 200;
} else {
if (rem >= 100) centuries = 1, rem -= 100;
else centuries = 0;
}
if (!rem) {
*is_leap = 0;
leaps = 0;
} else {
leaps = rem / 4U;
rem %= 4U;
*is_leap = !rem;
}
}
leaps += 97*cycles + 24*centuries - *is_leap;
return (year-100) * 31536000LL + leaps * 86400LL + 946684800 + 86400;
}
static int
__month_to_secs(int month, int is_leap)
{
static const int secs_through_month[] = {
0, 31*86400, 59*86400, 90*86400,
120*86400, 151*86400, 181*86400, 212*86400,
243*86400, 273*86400, 304*86400, 334*86400 };
int t = secs_through_month[month];
if (is_leap && month >= 2) t+=86400;
return t;
}
time_t tm_to_secs(const struct tm *tm)
{
int is_leap;
long long year = tm->tm_year;
int month = tm->tm_mon;
if (month >= 12 || month < 0) {
int adj = month / 12;
month %= 12;
if (month < 0) {
adj--;
month += 12;
}
year += adj;
}
long long t = __year_to_secs(year, &is_leap);
t += __month_to_secs(month, is_leap);
t += 86400LL * (tm->tm_mday-1);
t += 3600LL * tm->tm_hour;
t += 60LL * tm->tm_min;
t += tm->tm_sec;
return t;
}
|
