When alarm is activated a small sign and hour for alamr is with whilte
when alarm is deactivated sign and hour is with blue colour.
and the sketch is TFT_DigitalClock_RTC1d.ino.
I made a movie named adjuting clock with alarm & thermometer using DS3231 on 1.8" ST7735 display when you can see who the clock work:
PS: I made some changes in last sketch to store hour and state of alarm in EEPROM memory of ATmega, see TFT_DigitalClock_RTC1e.ino !!!