C++寫的一個計算兩個日期之間天數的小程序：

1. #include <Windows.h>
2. #include <stdio.h>
5. struct tagDate
6. {
7. int year;
8. int month;
9. int day;
10. };
12. //設置日期
13. void SetDate(int y, int m, int d, tagDate *date)
14. {
15. date->year = y;
16. date->month = m;
17. date->day = d;
18. }
20. //是否閏年
21. int IsLeapYear(int year)
22. {
23. return ((year%4==0) && (year%100!=0)||year%400==0);
24. }
26. //得到date.month的最大天數
27. int GetLastDay(tagDate date)
28. {
29. int num;
30. switch(date.month)
31. {
32. case 1:
33. case 3:
34. case 5:
35. case 7:
36. case 8:
37. case 10:
38. case 12:
39. num=31;
40. break;
41. case 2:
42. num = 28+IsLeapYear(date.year);
43. break;
44. default:
45. num = 30;
46. }
47. return num;
48. }
50. //日期是否合法
51. int IsDateValid(tagDate date)
52. {
53. if(date.year <0 || date.month <1 || date.month> 12)
54. return 0;
56. if(date.day <1 || date.day> GetLastDay(date))
57. return 0;
59. return 1;
60. }
62. //date+1
63. void AddDay(tagDate *date)
64. {
65. date->day++;
66. if(date->day > GetLastDay(*date))
67. {
68. date->day = 1;
69. date->month++;
70. if(date->month > 12)
71. {
72. date->month = 1;
73. date->year++;
74. }
75. }
76. }
78. //date1比date2小返回值為1，否則為0
79. int Compare(tagDate date1, tagDate date2)
80. {
81. if(date1.year < date2.year)
82. return 1;
83. if(date1.year <= date2.year && date1.month < date2.month)
84. return 1;
85. if(date1.year <= date2.year && date1.month <= date2.month && date1.day < date2.day)
86. return 1;
88. return 0;
89. }
90. //計算兩個日期的間隔天數
91. long DateDiff(tagDate date1, tagDate date2)
92. {
93. long delta = 0;
94. tagDate date3;
95. //若date1 > date2,交換date1,date2
96. if(!Compare(date1, date2))
97. {
98. date3 = date2;
99. date2 = date1;
100. date1 = date3;
101. }
103. //date1比date2少時，date1日期加1
104. while(Compare(date1,date2))
105. {
106. AddDay(&date1);
107. delta++;
108. }
109. return delta;
110. }
112. void main()
113. {
114. tagDate date1, date2;
115. int y, m, d;
117. system("cls");
118. while(1)
119. {
120. puts("\nInput date1\t ");
121. scanf("%d,%d,%d", &y, &m, &d);
122. SetDate(y, m, d, &date1);
123. if(!IsDateValid(date1))
124. {
125. puts( "date1 is invalid !");
126. exit(1);
127. }
129. puts("\nInput date2\t ");
130. scanf("%d,%d,%d", &y, &m, &d);
131. SetDate(y, m, d, &date2);
132. if(!IsDateValid(date2))
133. {
134. puts( "date2 is invalid !");
135. exit(1);
136. }
137. //
138. printf("\nResult : [%ld]", DateDiff(date1,date2));
139. }
140. }

https://blog.csdn.net/hellokandy/article/details/52194332

C++ 計算任意兩個日期之間的天數