看代码：

 1 #include <stdio.h>
 2 #include <time.h>
 3 
 4 char s[100];
 5 
 6 time_t StringToDatetime (const char *strTime)  
 7 {  
 8     if (NULL == strTime)  
 9     {  
10         return 0;  
11     }  
12     tm tm_;  
13     int year, month, day, hour, minute,second;  
14     sscanf(strTime,"%d-%d-%dT%d:%d:%d", &year, &month, &day, &hour, &minute, &second);  
15     tm_.tm_year  = year-1900;  
16     tm_.tm_mon   = month-1;  
17     tm_.tm_mday  = day;  
18     tm_.tm_hour  = hour;  
19     tm_.tm_min   = minute;  
20     tm_.tm_sec   = second;  
21     tm_.tm_isdst = 0;  
22   
23     time_t t_ = mktime(&tm_); //已经减了8个时区  
24     return t_; //秒时间  
25 }
26 
27 void DatetimeToString (time_t time)
28 {
29     time_t t = time + 28800;//8h 时区差
30     struct tm *p;
31     p = gmtime(&t);
32     strftime(s, sizeof(s), "%Y-%m-%dT%H:%M:%S", p);
33 }
34 
35 int main(int argc, const char * argv[])
36 {
37     time_t t;
38     t=1479794342;//s
39     DatetimeToString(t);
40     printf("%lld: %s
", t, s);
41     printf("%s", ctime(&t));
42     time_t t2 = t + 28800;
43     printf("%s", asctime(gmtime(&t2)));
44     printf("%s: %lld
", s, StringToDatetime(s));
45 
46     return 0;
47 } 

可以在下面网址进行测试：http://tool.chinaz.com/Tools/unixtime.aspx