I just disassembled an electric clock, and found a clock crystal inside, I presume it is 32768kHz
That made me wonder: Why are clock x-tals always this frequence, or are they ? Are they generally more precise than for example a 16mHz x-tal, or is it the lower frequence that make them more precise. By looking around I can see the precission for clock x-tals are 10-15 ppm (which as far as I have seen is parts per million)
So I was wandering: if I used my clock crystal on a ATTiny85 I might get a DIY RTC?