Greenhouse Controller using the ATmega328

I’m using the ATtiny85 as a real-time clock because the 20MHz crystal I bought doesn’t seem to be very accurate (I can see a difference with my stopwatch within a couple minutes :O) and the ATmega328 can’t do it because the program loop takes a maximum of 100ms. Plus, now I don’t have to worry about temperature differences causing issues either. I have a pin for seconds, minutes, hours, and days. After one second, the second pin will go from low to high, then from high to low after another second, etc for all pins.