Sorry, it was some time ago and I deleted that code.
Thank for that library, and I think I will try this one: GitHub - sleemanj/DS3231_Simple: An Arduino Library for EASY communication with DS3231 I2C RTC Clock and Atmel AT24C32 I2C EEPROM commonly found on the same board. Implements setting, getting the time/date, setting, checking and clearing alarms, and dead-easy circular-buffered logging of data with timestamp.