You'll need an RTC that uses SPI like the SparkFun DeadOn RTC (DS3234). Most RTC boards use I2C and will have an address conflict with the ADC chip on the Industruino, see this post:
As far as I know, Industruino doesn't have a RTC onboard.
The best solution is to get a DS1307 RTC and connect it to the I2C pins.
This can be done externally or internally.
Then there are many libraries available.
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