The following video shows a DIY real time clock using DS1307 and PIC12F1822 microcontroller. Time and date are displayed on 1602 LCD display, with the help of shift register this display uses only two wires. Time and date can be easily adjusted using two push buttons as shown in the video.
This picture show a LCD display with an I2C interface probably a PCF8754
so the dialogue is trought I2C Bus 2 wires SCL & SDA + power supply => 4 wires
PIC12F1822 is a dip8 MCU !
i suppose the PIC12F1822 use I2C Bus to dialogue with RTC DS1307 and LCD ( with 2 wires)