Adafruit have sevarl I2C based RTC, and according to the tutorial for the LCD shield it only uses
I am aware that you can share multiple device on I2C but I don´t really understand what is meant with "stick i2c-based...". There is no extra pins on the shield for SCL and SDA, so I don´t understand where I would "stick" the i2c RTC?the two I2C pins on the Pi! The best part is you don't really lose those two pins either, since you can stick i2c-based sensors, RTCs, etc and have them share the I2C bus.