The datasheet for the DS3231 explains that this part is an "Extremely Accurate I²C-Integrated RTC/TCXO/Crystal". And, hey, it does exactly what it says on the tin! This Real Time Clock (RTC) is the most precise you can get in a small, low power package. https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2021-04-06 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-05-17 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-08-17 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-09-01 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-10-14 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-10-21 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-11-21 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2022-12-01 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-02-14 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-03-13 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-03-14 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-03-15 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-03-16 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-08-11 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-08-23 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-11-21 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2023-11-28 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2024-02-29 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2024-03-15 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2024-11-27 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2024-12-03 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-02-22 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-03-03 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-04-26 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-05-12 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-08-08 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-08-21 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-11-23 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2025-12-02 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2026-01-31 https://elecena.pl/product/17498774/adafruit-ds3231-precision-rtc-breakout 2026-02-16