Computers, technology and software
Programmers’ Day is celebrated on the 256th day of the year – chosen because this is the number of distinct values that can be represented with an eight-bit byte, and the highest power of two which is less than 365.
Lots of people celebrate this day on January 7th, which seems to be the original (though unofficial) date for the celebration. In 2009, however, the government of Russia declared the day to be a professional holiday, and set the date as September 13th (Sept 12th on leap years)