The Pi RTC is based on the DS1307 clock chip and can provide a Real Time Clock (RTC) for Raspberry Pi via the I2C interface. The real-time clock of this module counts seconds, minutes, hours, day of the month, month, day of the week, and year with leap-year compensation valid up to 2100. The clock operates in 24-hour or 12-hour format with AM/PM indicator. If you wish to maintain this module's timing when the Raspberry Pi is powered off, you must insert a 3-Volt CR1225 lithium cell into the battery holder.

Note: Battery is not included.

Features

Supports Raspberry Pi 2/3/4 B/B+ Zero
Supports seconds, minutes, hours, day of the week, month, year
Supports 24-hour or 12-hour format with AM/PM indicator
56-byte battery-backed, non-volatile (NV) RAM for data storage
Two-wire serial interface
Programmable square-wave output signal
Automatic power-fail detection and switchover circuitry