https://en.wikipedia.org/wiki/Potrzebie wrote:
<<In issue 33, Mad published a partial table of the "Potrzebie System of Weights and Measures", developed by 19-year-old

Donald E. Knuth, later a famed computer scientist. According to Knuth, the basis of this new revolutionary system is the potrzebie, which equals the thickness of Mad issue 26, or 2.263348517438173216473 mm. A standardization in terms of the wavelength of the red line of the emission spectrum of cadmium is also given, which if the 1927 definition of the Ångstrom is taken for the value of that wavelength, would equal 2.263347539605392 mm.

Volume was measured in ngogn (equal to 1000 cubic potrzebies), mass in blintz (equal to the mass of 1 ngogn of halavah, which is "a form of pie [with] a specific gravity of 3.1416 and a specific heat of .31416"), and time in seven named units (decimal powers of the average earth rotation, equal to 1 "clarke"). The system also features such units as whatmeworry, cowznofski, vreeble,

**hoo and hah**.

According to the "Date" system in Knuth's article, which substitutes a 10-clarke "mingo" for a month and a 100-clarke "cowznofski", for a year, the date of October 29, 2007, is rendered as "Cal 7, 201 C. M." (for Cowznofsko Madi, or "in the Cowznofski of our MAD"). The dates are calculated from October 1, 1952, the date MAD was first published. Dates before this point are referred to, tongue-in-cheek, as "B.M." ("Before MAD.") The ten "Mingoes" are: Tales (Tal.) Calculated (Cal.) To (To) Drive (Dri.) You (You) Humor (Hum.) In (In) A (A) Jugular (Jug.) Vein (Vei.)

Google's calculator and Wolfram Alpha can perform conversions between potrzebies and other units.>>