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.
Most RTCs use an external 32kHz timing crystal..
A Feather board without ambition is a Feather board without FeatherWings! This is the DS3231 Precision RTC FeatherWing: it adds an extremely accurate I2C-integrated Real Time Clock (RTC) with a Temperature Compensated Crystal Oscillator (TCXO) to any Feather main board. This RTC is the most pr..