Simple digital calendar with LED displays
The top left button is clock it should be connected to the digital clocks and switch on when the new day came [Every 0:00 (12 a.m.)]. The top middle button is month switching key.
The right lower logic source should be activated only for leap-years (every 4 years since 2000).
The green LED's are days and lower yellow LED is month display:
0 = January
1 = February
2 = March
3 = April
4 = May
5 = June
6 = July
7 = August
8 = September
9 = October
a = November
b = December
