RTC_WDAY_MASK
tm->tm_wday = (ds1685_rtc_bcd2bin(rtc, wday, RTC_WDAY_MASK,
RTC_WDAY_MASK) - 1);
wday = ds1685_rtc_bin2bcd(rtc, (tm->tm_wday + 1), RTC_WDAY_MASK,
RTC_WDAY_MASK);
tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;
(RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))