Real Time Clock/ RTC DS1302 - clock breakout board/module
Product information:
A clock for your Arduino! With this module your Arduino always has the correct time and date, even when the power goes out.
Because the clock has its own battery it will always keep running. Up to 7 years on 1 battery!
The DS1302 communicates with the Arduino using a "3-wire interface" (CE, I/O, SCLK).
Dimensions: 2.9 x 2.6cm
Battery rechargeable (not included): LIR2032
Battery non-rechargeable (not included): CR2032
For a library, see:
https://www.RinkyDinkElectronics.com
Click to view the product's website.