Question

请参阅以下代码：

#include <iostream>
#include <stdlib.h>
#include <time.h>

using namespace std;

int main(void)
{
      time_t current_time = 1270715952;
      cout << "Subscriber current timestamp:" << current_time << endl;
      tm* currentTm = localtime(&current_time);
      char tmp_str[256];
      //2010-04-08T11:39:12
      snprintf(tmp_str,
         sizeof(tmp_str),
         "%04d%02d%02d%02d%02d%02d.000",
         currentTm->tm_year+1900,
         currentTm->tm_mon+1,
         currentTm->tm_mday,
         currentTm->tm_hour,
         currentTm->tm_min,
         currentTm->tm_sec);
      cout << "Subscriber current date:" << tmp_str << endl;
      tm tmpDateScheduleFrom, tmpDateScheduleTo;
      memset(&tmpDateScheduleFrom, 0, sizeof(tm));
      memset(&tmpDateScheduleTo, 0, sizeof(tm));
      //2010-04-08T11:00
      tmpDateScheduleFrom.tm_sec  = 0;
      tmpDateScheduleFrom.tm_min  = 0;
      tmpDateScheduleFrom.tm_hour = 11;
      tmpDateScheduleFrom.tm_mday = 8;
      tmpDateScheduleFrom.tm_mon  = 3;
      tmpDateScheduleFrom.tm_year = 110;
      //2010-04-08T12:00
      tmpDateScheduleTo.tm_sec  = 0;
      tmpDateScheduleTo.tm_min  = 0;
      tmpDateScheduleTo.tm_hour = 12;
      tmpDateScheduleTo.tm_mday = 8;
      tmpDateScheduleTo.tm_mon  = 3;
      tmpDateScheduleTo.tm_year = 110;
      time_t localFrom   = mktime(&tmpDateScheduleFrom);
      time_t localTo     = mktime(&tmpDateScheduleTo);
      cout << "Subscriber current timestamp:" << current_time << endl;
      cout << "Subscriber localFrom:" << localFrom << endl;
      cout << "Subscriber localTo:" << localTo << endl;
      return 0;
}

结果如下：

Subscriber current timestamp:1270715952
Subscriber current date:20100408113912.000
Subscriber current timestamp:1270715952
Subscriber localFrom:1270717200
Subscriber localTo:1270720800

为什么当前用户时间戳（用户日期和时间：2010-04-08T11：39：12）不在范围localFrom（日期/时间的时间戳：2010-04-08T11：00：00）和LocalTo（日期/时间的时间戳：2010-04-08T12：00：00）？

Answer 1

我认为问题是您将tm_isdst设置为0，这意味着no DST，但localtime()使用系统范围的DST设置。

如果您将tm_isdst设置为1，一切都应该没问题。根据{{1}}，如果您不确定，可以为man mktime设置负值。 tm_isdst没有明确说明，但我想在这种情况下man也会使用系统设置，就像mktime()一样。

localtime和mktime的时间戳问题

1 个答案: