struct tm {     int tm_sec;   /* seconds after the minute - [0,59] */     int tm_min;   /* minutes after the hour - [0,59] */     int tm_hour;  /* hours since midnight - [0,23] */     int tm_mday;  /* day of the month - [1,31] */     int tm_mon;   /* months since January - [0,11] */     int tm_year;  /* years since 1900 */     int tm_wday;  /* days since Sunday - [0,6] */     int tm_yday;  /* days since January 1 - [0,365] */     int tm_isdst;  /* daylight savings time flag */     }; 

struct timeval {     time_t    tv_sec;   /* seconds */     suseconds_t  tv_usec; /* microseconds */ };

time_t time(time_t *t); //取得從1970年1月1日至今的秒數(shù) char *asctime(const struct tm *tm); //將結(jié)構(gòu)中的信息轉(zhuǎn)換為真實(shí)世界的時(shí)間，以字符串的形式顯示 char *ctime(const time_t *timep); //將timep轉(zhuǎn)換為真是世界的時(shí)間，以字符串顯示，它和asctime不同就在于傳入的參數(shù)形式不一樣 struct tm *gmtime(const time_t *timep); //將time_t表示的時(shí)間轉(zhuǎn)換為沒(méi)有經(jīng)過(guò)時(shí)區(qū)轉(zhuǎn)換的UTC時(shí)間，是一個(gè)struct tm結(jié)構(gòu)指針  struct tm *localtime(const time_t *timep); //和gmtime類似，但是它是經(jīng)過(guò)時(shí)區(qū)轉(zhuǎn)換的時(shí)間。 time_t mktime(struct tm *tm); //將struct tm 結(jié)構(gòu)的時(shí)間轉(zhuǎn)換為從1970年至今的秒數(shù) int gettimeofday(struct timeval *tv, struct timezone *tz); //返回當(dāng)前距離1970年的秒數(shù)和微妙數(shù)，后面的tz是時(shí)區(qū)，一般不用 double difftime(time_t time1, time_t time2); //返回兩個(gè)時(shí)間相差的秒數(shù) 

time_t t; //秒時(shí)間 tm* local; //本地時(shí)間  tm* gmt;  //格林威治時(shí)間 char buf[128]= {0};  t = time(NULL); //或者time(&t);//獲取目前秒時(shí)間 local = localtime(&t); //轉(zhuǎn)為本地時(shí)間 strftime(buf, 64, "%Y-%m-%d %H:%M:%S", local); std::cout << buf << std::endl;  gmt = gmtime(&t);//轉(zhuǎn)為格林威治時(shí)間 strftime(buf, 64, "%Y-%m-%d %H:%M:%S", gmt); std::cout << buf << std::endl; 

 tm tm_; time_t t_; char buf[128]= {0};  strcpy(buf, "2012-01-01 14:00:00"); strptime(buf, "%Y-%m-%d %H:%M:%S", &tm_); //將字符串轉(zhuǎn)換為tm時(shí)間 tm_.tm_isdst = -1; t_ = mktime(&tm_); //將tm時(shí)間轉(zhuǎn)換為秒時(shí)間 t_ += 3600; //秒數(shù)加3600  tm_ = *localtime(&t_);//輸出時(shí)間 strftime(buf, 64, "%Y-%m-%d %H:%M:%S", &tm_); std::cout << buf << std::endl;  

time_t StringToDatetime(char *str) {   tm tm_;   int year, month, day, hour, minute,second;   sscanf(str,"%d-%d-%d %d:%d:%d", &year, &month, &day, &hour, &minute, &second);   tm_.tm_year = year-1900;   tm_.tm_mon  = month-1;   tm_.tm_mday = day;   tm_.tm_hour = hour;   tm_.tm_min  = minute;   tm_.tm_sec  = second;   tm_.tm_isdst = 0;    time_t t_ = mktime(&tm_); //已經(jīng)減了8個(gè)時(shí)區(qū)   return t_; //秒時(shí)間 } 

struct timeval start_time, over_time, consume_time;gettimeofday(&over_time, NULL);//get the current timestart_time = over_time; do something.....gettimeofday(&over_time, NULL);timeval_subtract(&consume_time, &start_time, &over_time);//計(jì)算時(shí)間差104./**    * 計(jì)算兩個(gè)時(shí)間的間隔，得到時(shí)間差    * @param struct timeval* resule 返回計(jì)算出來(lái)的時(shí)間    * @param struct timeval* x 需要計(jì)算的前一個(gè)時(shí)間    * @param struct timeval* y 需要計(jì)算的后一個(gè)時(shí)間    * return -1 failure ,0 success  **/ timeval_subtract(struct timeval* result, struct timeval* x, struct timeval* y)  {     if ( x->tv_sec>y->tv_sec )          return -1;       if ( (x->tv_sec==y->tv_sec) && (x->tv_usec>y->tv_usec) )          return -1;       result->tv_sec = ( y->tv_sec-x->tv_sec );     result->tv_usec = ( y->tv_usec-x->tv_usec );       if (result->tv_usec<0)     {          result->tv_sec--;          result->tv_usec+=1000000;     }       return 0;  }