The Seeed Pi RTC is based on the DS1307 clock chip and can provide a real-time clock (RTC) for your Raspberry Pi via the I2C interface. The real-time clock of this module counts seconds, minutes, hours, date of the month, month, day of the week and year, with leap-year compensation valid up to 2100. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. If you want to keep this module timing when the Raspberry Pi is powered off, you need to put a 3-Volt CR1225 lithium cell in the battery holder. Features * Supports all models of Raspberry Pi Model B or A * Supports seconds, minutes, hours, day of week, month, year * Supports 24-hour or 12-hour format with AM/PM indicator * 56-byte, battery-backed, nonvolatile (NV) RAM for data storage * Programmable squarewave output signal * Automatic power-fail detect and switch circuitry * Product number: Seeed 103030277 Pinout Specifications Dimensions 30mm x23mm x15mm Weight 13.2g Battery CR1225 (not included) Package Contents * 1x Pi RTC (DS1307) * 1x 2-pin header Battery NOT included Resources * Product Wiki * Seeed Pi RTC Library * DS1307 Datasheet * Eagle Files https://elecena.pl/product/22944989/pi-rtc-ds1307 2023-03-17 https://elecena.pl/product/22944989/pi-rtc-ds1307 2023-12-27 https://elecena.pl/product/22944989/pi-rtc-ds1307 2024-09-18 https://elecena.pl/product/22944989/pi-rtc-ds1307 2024-11-29 https://elecena.pl/product/22944989/pi-rtc-ds1307 2024-11-30 https://elecena.pl/product/22944989/pi-rtc-ds1307 2025-07-22 https://elecena.pl/product/22944989/pi-rtc-ds1307 2025-11-28 https://elecena.pl/product/22944989/pi-rtc-ds1307 2025-11-29