time

1.获得系统时间

time(NULL);

2.时间戳转换成日期

#include <iostream>
#include <time.h>
using namespace std;

int main()
{
	char szBeginTime[32] ={0};
	time_t tmBeginTime = time(NULL);
	struct tm *tmNowBegin = localtime(&tmBeginTime);
	strftime(szBeginTime,32,"%Y-%m-%d %H:%M:%S",tmNowBegin);
	fprintf(stderr, "%s\n", szBeginTime );
	system("pause");
	return 0;
}

3.时间戳和日期相互转换

#include <stdio.h>
#include <time.h>
#include <iostream>
using namespace std;
/*
char *pValue = "2011-12-10 11:29:08";
sscanf(pValue, "%d-%d-%d %d:%d:%d", &pRole->Y,&pRole->Online_lastM,&pRole->Online_lastD,&pRole->h,&pRole->m,&pRole->s);
*/
int main(void)
{
	time_t timep;
	struct tm *p;
	time(&timep);
	printf("time() : %d \n",timep);
	p=localtime(&timep);
	timep = mktime(p);
	printf("time()->localtime()->mktime():%d\n",timep);
	system("pause");
	return 0;
}

4.计算一年中的第几天
 

#include<iostream>
using namespace std;

int main()
{
	int year,month,day;
	int m[12]={31,28, 31,30,31,30,31,31,30,31,30,31};
	cout<<"请输入年月日(空格隔开)：";
	cin>>year>>month>>day;
	if(year%400==0 || year%4==0 && year%100!=0)
		m[1]=29;
	int sumdays=0;
	for(int i=0;i<month-1;i++){
		sumdays+=m[i];
	}
	sumdays+=day;
	cout<<year<<"年"<<month<<"月"<<day<<"日是一年中的第"<<sumdays<<"天"<<endl;
	system("pause");
	return 0;
}

#include<iostream>
#include <stdio.h> 　　
#include <stddef.h> 　　
#include <time.h>
using namespace std;

int main()
{
	time_t tmBeginTime = time(NULL);
	struct tm *tmNowBegin = localtime(&tmBeginTime);
	if (NULL == tmNowBegin)
		return false;
	int nCreateYear = tmNowBegin->tm_year+1900;
	int nCreateMon = tmNowBegin->tm_mon+1;
	int nCreateDay = tmNowBegin->tm_mday;
	int nCreateYearDay = tmNowBegin->tm_yday;
	int nCreateWeek = tmNowBegin->tm_wday;
	cout<<nCreateYear<<","<<nCreateMon<<","<<nCreateDay<<","<<nCreateYearDay<<","<<nCreateWeek<<endl;
	system("pause");
	return 0;	
}

5.Linux time

localtime 和 localtime_r

http://blog.csdn.net/maocl1983/article/details/6221810

Linux下面time.h时间函数总结

http://blog.csdn.net/likun_tech/article/details/7317536

判断两个时间是同一天

bool IsToday(time_t nLastTime, time_t nNowTime)
{
 time_t LastTime = nLastTime;
 struct tm localTime;
 localtime_r(&LastTime, &localTime);
 time_t NowTime = nNowTime;
 struct tm localNowTime;
 localtime_r(&NowTime, &localNowTime);
 if (localTime.tm_year == localNowTime.tm_year &&
   localTime.tm_mon == localNowTime.tm_mon &&
   localTime.tm_mday == localNowTime.tm_mday)
 {
  return true;
 }
 else
  return false;
}
//扩展
bool CTimer::IsToday() const
{
 if (m_Time == 0)
  return false;
 time_t NowTime = time(NULL);
    struct tm localNowTime;
    localtime_r(&NowTime, &localNowTime);

 struct tm localTime;
    localtime_r(&m_Time, &localTime);

 if (localTime.tm_year == localNowTime.tm_year &&
   localTime.tm_mon == localNowTime.tm_mon &&
   localTime.tm_mday == localNowTime.tm_mday)
 {
  return true;
 }
 else
  return false;
}

bool CTimer::IsThisWeek() const
{
 if (m_Time == 0)
  return false;
 time_t NowTime = time(NULL);
 struct tm localNowTime;
 localtime_r(&NowTime, &localNowTime);

 struct tm localTime;
 localtime_r(&m_Time, &localTime);

 return (localTime.tm_year == localNowTime.tm_year &&
 (localTime.tm_yday - localNowTime.tm_yday) == (GetWeek7Day(m_Time) - GetWeek7Day(NowTime)));
}

int CTimer::GetWeek7Day(time_t tTime) const
{
 struct tm localNowTime;
 localtime_r(&tTime, &localNowTime);
 return localNowTime.tm_wday == 0 ? 7 : localNowTime.tm_wday;
}

bool CTimer::IsThisMonth() const
{
 if (m_Time == 0)
  return false;
 time_t NowTime = time(NULL);
 struct tm localNowTime;
 localtime_r(&NowTime, &localNowTime);

 struct tm localTime;
 localtime_r(&m_Time, &localTime);

 return (localTime.tm_year == localNowTime.tm_year &&
   localTime.tm_mon == localNowTime.tm_mon);
}

bool CTimer::IsYesterday() const
{
    time_t NowTime = time(NULL);
    struct tm local;
    localtime_r(&NowTime, &local);
    struct tm LoaclTime;
    localtime_r(&m_Time, &LoaclTime);
    if (LoaclTime.tm_year != local.tm_year)
        return false;

    return (local.tm_yday - LoaclTime.tm_yday) == 1;
}

time_t CTimer::GetSunday() const
{
 time_t NowTime = time(NULL);
 struct tm local;
 localtime_r(&NowTime, &local);
 local.tm_mday = local.tm_mday - local.tm_wday + 1; //加1表示星期一的零时
 local.tm_hour = 0;
 local.tm_min = 0;
 local.tm_sec = 0;
 time_t Sunday = mktime(&local);
 return Sunday;
}

int CTimer::GetYear() const
{
 struct tm localNowTime;
 localtime_r(&m_Time, &localNowTime);
 return localNowTime.tm_year + 1900;
}
int CTimer::GetMonth() const
{
 struct tm localNowTime;
 localtime_r(&m_Time, &localNowTime);
 return localNowTime.tm_mon + 1;
}
int CTimer::GetDay() const
{
 struct tm localNowTime;
 localtime_r(&m_Time, &localNowTime);
 return localNowTime.tm_mday;
}
int CTimer::GetHour() const
{
 struct tm localNowTime;
 localtime_r(&m_Time, &localNowTime);
 return localNowTime.tm_hour;
}
int CTimer::GetMinute() const
{
    struct tm localNowTime;
    localtime_r(&m_Time, &localNowTime);
 return localNowTime.tm_min;
}
int CTimer::GetSecond() const
{
    struct tm localNowTime;
    localtime_r(&m_Time, &localNowTime);
 return localNowTime.tm_sec;
}
int CTimer::GetYearDay() const
{
    struct tm localNowTime;
    localtime_r(&m_Time, &localNowTime);
    return localNowTime.tm_yday;
}

int CTimer::Get12Clock() const
{
 struct tm localNowTime;
 localtime_r(&m_Time, &localNowTime);
 localNowTime.tm_mday = localNowTime.tm_mday + 1;
 localNowTime.tm_hour = 0;
 localNowTime.tm_min = 0;
 localNowTime.tm_sec = 0;
 time_t tToNight = mktime(&localNowTime);
 return tToNight - m_Time;
}
time_t CTimer::GetDate() const
{
  struct tm localNowTime;
  localtime_r(&m_Time, &localNowTime);
 localNowTime.tm_hour = 0;
 localNowTime.tm_min = 0;
 localNowTime.tm_sec = 0;
 time_t date = mktime(&localNowTime);
 return date;
}
int CTimer::GetWeekDay() const
{
    struct tm localNowTime;
    localtime_r(&m_Time, &localNowTime);
	return localNowTime.tm_wday;
}