& an extra day

29 different ampersands to celebrate Leap Day,
from Calligraphy Alphabets Made Easy. 

If you count up the capitals and small letters, you have an alphabet of 52--one for each week of the year.  But what about that extra day in Leap Year?  There's no better symbol for this year's leap than the ampersand.

By the the mid-19th century the ampersand was recited by English-speaking students as the 27th letter of the alphabet.  Its name comes from a dog Latin pronunciation of and per se and, which means "and by itself and."