A 7-segment clock based on the ATMEGA 328p, MAX7219 led driver, a DS1307 RTC and some old HP calculator common-cathode bubble lens displays.

Clock features:
- displays time: hh.mm.ss A.
  if 12-hour, shows A or P
  if alarm set, shows . in the A/P position
- displays date: mm.dd.yy D
  shows the day of week 1-7 at D
- when the date display is selected, the time scrolls over while still keeping time to reveal the date, pauses, and then scrolls back
- during set mode, the selected value blinks
- allows for start/stop schedule for DST, as well as disabling DST conversion
- DST conversion also works during time set; if in DST, the time is converted back to STD for the RTC
- RTC stores time in STD local time
- alarm function allows none, weekends, weekdays and all days schedule

Includes free Nyan Cat alarm tune. Tunes are made with the miditones utility and played via the Playtune library.

Note that though there are three timers on the ATMEGA 328p we use timer0 for millis() so we limit Playtune polyphony to two notes.