WEEKS_REG
I2C_WRITE(sc, WEEKS_REG, bintobcd(dt->dt_wday == 0 ? 7 : dt->dt_wday));
dt->dt_wday = bcdtobin(I2C_READ(sc, WEEKS_REG));
weeks_reg = POWER_READ(sc, WEEKS_REG);
POWER_WRITE(sc, WEEKS_REG, bintobcd(dt->dt_wday));