DS1305_HR_12
if (bcd & DS1305_HR_12) {
bcd &= ~DS1305_HR_12;
return DS1305_HR_12 | bin2bcd(hour);
return DS1305_HR_12 | DS1305_HR_PM | bin2bcd(hour);
ds1305->hr12 = (DS1305_HR_12 & value) != 0;