From a website on the matter:
Sometimes you'll have a nice date packed such "03/09/01" which you know to mean March 9, 2001. However, some cases will use a different form such as "1068". In this case, the first number "1" stands for the year (2001) and the next three numbers indicate which day of the year (365 days in a year) it was packed. So "068" would be day 68 of the year 2001...or March 9, 2001.
Almost every component that goes into an MRE has a date code stamped on it in the form "0132" (see above explanation). Everything from entrees, crackers, peanut butter, accessory packs, etc. - they all have date codes. If you can open up your MRE, you should be able to figure out how old each piece is.
So this one would be the 139th day of 2001.
They used a four-digit number. The year is represented only by the first digit, representing the last digit of the year?
So that means the numbers recycle
every decade, and there's really no way to tell, at a glance, whether a given MRE individual meal pack was made in 1997 or 2007 unless you know, specifically, what menu number corresponds to the entree?
Why was it so hard for them to just put the
entire date in six digits? Why did they have to use something so...unusual, in the form of only one digit for the year and three digits for the day of year?
This one:
The 243rd of a year ending in "8".
If someone finds this when they're hungry next year, or someone is buying surplus, how will they know if it means 1998 or 2008?