计算星期几的c代码.txt

这是一个计算星期几的源码

计算星期几的C代码

static UCHAR   ClkDay;               /* Counters for local DATE */
static UCHAR   ClkDOW;               /* Day of week (0 is Sunday) */
static UCHAR   ClkMonth;
static UINT    ClkYear;

typedef struct clk_month 
{         
    UCHAR  MonthDays;                /* Number of days in each month */
    char  *MonthName;                /* Name of the month */
    UCHAR  MonthVal;                 /* Value used to compute day of the week */
} CLK_MONTH;


static CLK_MONTH code ClkMonthTbl[] = {    /* MONTHS TABLE */
    {0,  "",           0},             /* Invalid month */
    {31, "January ",   6},             /* January */
    {28, "February ",  2},             /* February (note leap years are handled by code) */
    {31, "March ",     2},             /* March */
    {30, "April ",     5},             /* April */
    {31, "May ",       0},             /* May */
    {30, "June ",      3},             /* June */
    {31, "July ",      5},             /* July */
    {31, "August ",    1},             /* August */
    {30, "September ", 4},             /* September */
    {31, "October ",   6},             /* October */
    {30, "November ",  2},             /* November */
    {31, "December ",  4}              /* December */
};


/*
********************************************************************************
*************************
*                                         COMPUTE DAY-OF-WEEK
*
* Description : This function computes the day of the week (0 == Sunday) based 
on the current month,
*               day and year.
* Arguments   : None.
* Returns     : None.
* Notes       : - This function updates ClkDOW.
*               - This function is called by ClkUpdateDate().
********************************************************************************
*************************
*/
#if CLK_DATE_EN
static  void  ClkUpdateDOW (void)
{
    UINT dow;
    
    dow = ClkDay + ClkMonthTbl[ClkMonth].MonthVal;
    if (ClkMonth < 3)
    {
        if (ClkIsLeapYear(ClkYear)) 
        {
            dow--;
        }
    }
    dow    += ClkYear + (ClkYear / 4);
    dow    += (ClkYear / 400) - (ClkYear / 100);
    dow    %= 7;
    ClkDOW  = dow;
}
#endif