Retrieve and edit file timestamps in Windows.

filetime.c

#include <stdio.h>
#include <windows.h>

// FILETIME is always UTC. Note that Windows itself will display timestamps in your local timezone, e.g. in the file properties dialog.
// Error codes: http://msdn.microsoft.com/en-us/library/windows/desktop/ms681381(v=vs.85).aspx
// i686-w64-mingw32-gcc -o filetime filetime.c

int main(int argc, char *argv[]) {
  if (argc < 2) {
    fprintf(stderr, "Usage: filetime <file> [new mtime] ...\n");
    fprintf(stderr, "       filetime AltDrag.ini 20140102030405\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "Note: All times are in UTC!\n");
    fprintf(stderr, "      Date format: YYYYMMDDhhmmss\n");
    return 1;
  }

  HANDLE f = CreateFile(argv[1], FILE_READ_ATTRIBUTES, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
  if (f == INVALID_HANDLE_VALUE) {
    fprintf(stderr, "CreateFile() failed on line %d! Error code: %d.\n", __LINE__, GetLastError());
    return 2;
  }

  FILETIME mt;
  SYSTEMTIME st;
  if (GetFileTime(f,NULL,NULL,&mt) == 0) {
    fprintf(stderr, "GetFileTime() failed on line %d! Error code: %d.\n", __LINE__, GetLastError());
    return 2;
  }
  if (FileTimeToSystemTime(&mt,&st) == 0) {
    fprintf(stderr, "FileTimeToSystemTime() failed on line %d! Error code: %d.\n", __LINE__, GetLastError());
    return 2;
  }
  printf("file current mtime: %04d%02d%02d%02d%02d%02d\n", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
  printf("touch -d '%04d-%02d-%02d %02d:%02d:%02d UTC' %s\n", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, argv[1]);

  if (argc > 2) {
    char txt[10] = "";
    // YYYY
    strncpy(txt, argv[2]+0, 4);
    txt[4] = '\0';
    st.wYear = atoi(txt);
    // MM
    strncpy(txt, argv[2]+4, 2);
    txt[2] = '\0';
    st.wMonth = atoi(txt);
    // DD
    strncpy(txt, argv[2]+6, 2);
    st.wDay = atoi(txt);
    // hh
    strncpy(txt, argv[2]+8, 2);
    st.wHour = atoi(txt);
    // mm
    strncpy(txt, argv[2]+10, 2);
    st.wMinute = atoi(txt);
    // ss
    strncpy(txt, argv[2]+12, 2);
    st.wSecond = atoi(txt);

    printf("file new mtime: %04d%02d%02d%02d%02d%02d\n", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
    printf("touch -d '%04d-%02d-%02d %02d:%02d:%02d UTC' %s\n", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, argv[1]);

    f = ReOpenFile(f, FILE_WRITE_ATTRIBUTES, 0, 0);
    if (f == INVALID_HANDLE_VALUE) {
      fprintf(stderr, "ReOpenFile() failed on line %d! Error code: %d.\n", __LINE__, GetLastError());
      return 2;
    }
    if (SystemTimeToFileTime(&st,&mt) == 0) {
      fprintf(stderr, "SystemTimeToFileTime() failed on line %d! Error code: %d.\n", __LINE__, GetLastError());
      return 2;
    }
    if (SetFileTime(f,NULL,NULL,&mt) == 0) {
      fprintf(stderr, "SetFileTime() failed on line %d! Error code: %d.\n", __LINE__, GetLastError());
      return 2;
    }
  }

  CloseHandle(f);
  return 0;
}

filetime.exe