这是一个简单的问题，但解决方案似乎远非简单。我想知道如何将UTC时间转换为本地时间。我正在寻找C语言的标准解决方案，并且基本可以保证在任何计算机上的任何位置都能正常工作。
我仔细阅读了以下链接，但在那里找不到解决方案：
我已经尝试了许多变化，例如（datetime是带有UTC时间和日期的字符串）：
strptime(datetime, "%A %B %d %Y %H %M %S", tp);
strftime(printtime, strlen(datetime), "%A %B %d %Y %H %M %S", tp);
或者
strptime(datetime, "%A %B %d %Y %H %M %S", tp);
lt=mktime(tp);
printtime=ctime(<);
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
long long diff_tm(struct tm *a, struct tm *b)
{
return a->tm_sec - b->tm_sec
+60LL*(a->tm_min - b->tm_min)
+3600LL*(a->tm_hour - b->tm_hour)
+86400LL*(a->tm_yday - b->tm_yday)
+(a->tm_year-70)*31536000LL
-(a->tm_year-69)/4*86400LL
+(a->tm_year-1)/100*86400LL
-(a->tm_year+299)/400*86400LL
-(b->tm_year-70)*31536000LL
+(b->tm_year-69)/4*86400LL
-(b->tm_year-1)/100*86400LL
+(b->tm_year+299)/400*86400LL;
}
int main()
{
time_t utc, local;
char buf[100];
const char datetime[]="2013 11 30 23 30 26 UTC"; /* hard coded date and time in UTC */
struct tm *tp=malloc(sizeof(struct tm));
if(tp==NULL)
exit(-1);
struct tm *localt=malloc(sizeof(struct tm));
if(localt==NULL)
exit(-1);
memset(tp, 0, sizeof(struct tm));
memset(localt, 0, sizeof(struct tm));
printf("UTC date and time to be converted in local time: %s\n", datetime);
/* put values of datetime into time structure *tp */
strptime(datetime, "%Y %m %d %H %M %S %z", tp);
/* get seconds since EPOCH for this time */
utc=mktime(tp);
printf("UTC date and time in seconds since EPOCH: %d\n", utc);
/* lets convert this UTC date and time to local date and time */
struct tm e0={ .tm_year = 70, .tm_mday = 1 }, e1, new;
/* get time_t EPOCH value for e0 (Jan. 1, 1970) */
time_t pseudo=mktime(&e0);
/* get gmtime for this value */
e1=*gmtime(&pseudo);
/* calculate local time in seconds since EPOCH */
e0.tm_sec += utc - diff_tm(&e1, &e0);
/* assign to local, this can all can be coded shorter but I attempted to increase clarity */
local=e0.tm_sec;
printf("local date and time in seconds since EPOCH: %d\n", local);
/* convert seconds since EPOCH for local time into localt time structure */
localt=localtime(&local);
/* get nicely formatted human readable time */
strftime(buf, sizeof buf, "%Y-%m-%d %H:%M:%S %Z", localt);
printf("local date and time: %s\n", buf);
}
在大多数系统上，它应该无问题编译。我硬编码了一个UTC时间和日期，然后将其转换为本地时间和日期。
strptime）还是仅仅使用纯C语言？ - R.. GitHub STOP HELPING ICE