how to shrink a date down to a one digit number

If you are trying to represent a date, including the year, with one digit, you would need a number system with infinite characters, because each new day would call for a new character. Now, if you wanted to represent each day of the year with a number, you would only need 366 characters, as that is how many days are in a leap year.

I don't think you can do that.

The "Julian Date" of 1.2.2014 0:0:0 o'clock is 2456689.50000

The "Julian Date" of 1.2.2014 12:0:0 is 2456690.00000

The "Julian Date"

see:

http://aa.usno.navy.mil/data/docs/JulianDate.php

The Julian date for CE 2014 February 1 00:00:00.0 UT is JD 2456689.500000

The Julian date for CE 2014 February 1 12:00:00.0 UT is JD 2456690.000000 

The Julian date for CE 2014 May 29 12:00:00.0 UT is JD 2456807.000000 

Yes but Heureka, these are one number -NOT one digit!