By popular demand, I added time setting capabilities to BookClock. Time and date can now be set from two buttons, called "Menu" ("H/M" in the photo) and "Plus" ("+").
Press "Menu" to select between hours and minutes. Press "Plus" to increment the blinking selection. When done, just let it time out (about 4 seconds) and the time will be saved in the RTC.
Hold down "Menu" until the date, formatted as yy/mm/dd, is displayed. Press "Menu" again to select either year, month or day, then press "Plus" to increment the blinking value.
The time-setting code is copied and adapted from IllyClock and uses the same state-machine mechanism.
I connected the two buttons to D16 ("Plus") and D17 ("Menu").
The code, compilable on both Arduino 23 and 1.0, can be downloaded from here.