LoganPark:
I think I need to apply those operations somehow to my data before displaying the sprintf'ed string. Am I on the right track?
I don't have the clock chip you are using, but I am familiar with the Dallas (now Maxim) SmartClock chips (DS-1216).
They return all data as BCD numbers... for example, the current month (November) is returned as "0x11" which is actually 17 in decimal (your "off by six" problem?).
You have to take the upper 4 bits and multiply by 10, then add that to the lower 4 bits to get the decimal version of the BCD number.
Hope this helps....