How do I change the day of a watch that won't change with the date

I got a Sartego Sggn16 all for Christmas. Its a nice watch but the day won't change with the date. The directions chance that the morning won't change between 9pm and 4am. Even so if I change the day during that time the day won't change until noon of the...

Source: http://forums.techguy.org/miscellaneous-tech/1037846-how-do-i-change-day.html