c++中的 SYSTEMTIME 怎么用，有什么意思。

typedef struct _SYSTEMTIME {
WORD wYear;
WORD wMonth;
WORD wDayOfWeek;
WORD wDay;
WORD wHour;
WORD wMinute;
WORD wSecond;
WORD wMilliseconds;
} SYSTEMTIME;
Members
wYear
Specifies the current year.
wMonth
Specifies the current month; January = 1, February = 2, and so on.
wDayOfWeek
Specifies the current day of the week; Sunday = 0, Monday = 1, and so on.
wDay
Specifies the current day of the month.
wHour
Specifies the current hour.
wMinute
Specifies the current minute.
wSecond
Specifies the current second.
wMilliseconds
Specifies the current millisecond.

This function retrieves the current system date and time. The system time is expressed in UTC.

void GetSystemTime(
LPSYSTEMTIME lpSystemTime
);
Parameters
lpSystemTime
[out] Pointer to a SYSTEMTIME structure to