-
-
Notifications
You must be signed in to change notification settings - Fork 288
/
misc.c
75 lines (61 loc) · 1.36 KB
/
misc.c
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
/*
* Copyright (C) 1995. Bill Brown <brown@gis.uiuc.edu> & Michael Shapiro
*
* This program is free software under the GPL (>=v2)
* Read the file GPL.TXT coming with GRASS for details.
*/
#include <grass/datetime.h>
/*!
* \brief
*
* \param year
* \param ad
* \return int
*/
int datetime_is_leap_year(int year, int ad)
{
if (year == 0)
return datetime_error(-1, "datetime_is_leap_year(): illegal year");
if (!ad)
return 0; /* BC */
if (year < 0)
return 0; /* ?? */
return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
}
/*!
* \brief
*
* returns the number of days in 'year'
*
* \param year
* \param ad
* \return int
*/
int datetime_days_in_year(int year, int ad)
{
if (year == 0)
return datetime_error(-1, "datetime_days_in_year(): illegal year");
if (datetime_is_leap_year(year, ad))
return 366;
else
return 365;
}
/*!
* \brief
*
* returns number of days in 'month' of a particular 'year'
*
* \param month
* \param year
* \param ad
* \return int
*/
int datetime_days_in_month(int year, int month, int ad)
{
static int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
if (month < 1 || month > 12)
return datetime_error(-1, "datetime_days_in_month(): illegal month");
if (month == 2 && datetime_is_leap_year(year, ad))
return (29);
return (days[month - 1]);
}