Getting the current system time in milliseconds with C++

After doing quite a bit of C++ recently, I thought I would post my method for getting the current system time in milliseconds in C++ for both Mac OS X and Windows. The Mac version might translate to other Unix platforms, but you’ll have to check the docs or man pages.

Mac OS X

#include <sys/time.h>
timeval time;
gettimeofday(&time, NULL);
long millis = (time.tv_sec * 1000) + (time.tv_usec / 1000);

This actually returns a struct that has microsecond precision.

Windows

#include "windows.h"
SYSTEMTIME time;
GetSystemTime(&time);
WORD millis = (time.wSeconds * 1000) + time.wMilliseconds;

This code gives the milliseconds within the last minute. If you want milliseconds since epoch or some other fixed point in time it will require a bit more math on the SYSTEMTIME struct.

8 thoughts on “Getting the current system time in milliseconds with C++

  1. Can someone send a .cpp file, it won’t compile it says:
    gcc /Users/Alexandre/Desktop/timeInMS.cpp -o ~/Desktop/Time
    /usr/bin/ld: Undefined symbols:
    ___gxx_personality_v0
    collect2: ld returned 1 exit status

    Thank you!

    Like

  2. Shishir,

    You might want to use printf( “%ld”, millis ) to avoid the negative values.

    If you’re having trouble compiling this, try “struct timeval” instead of “timeval”.

    Like

  3. After a long search i have find the good code for Windows VC++.
    #include “windows.h”
    SYSTEMTIME time;
    GetSystemTime(&time);
    WORD millis = (time.wSeconds * 1000) + time.wMilliseconds;
    is working fine for getting the time in millisecond..

    Good code

    Like

  4. Hi,
    I am student of BSCS.. I am trying to learn c and c++ nowadays. I am a beginner so i can’t understand much about this time get code from windows. If anyone please please help … How can i code it in struct.. And if anyone could provide me some material of c++ or c to learn it best. I will be very thankful to him/her…. thankyou . umar

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  5. Just one correction: It’s not “wSeconds” it’s “wSecond”.

    In this line:
    WORD millis = (time.wSeconds * 1000) + time.wMilliseconds;

    Replace with:
    WORD millis = (time.wSecond * 1000) + time.wMilliseconds;

    Like

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