MRE Manufacturers use a 4-digit modified julian date code to indicate the manufacture date. This code is usually stamped on the MRE box and pouch. The location of the code can vary. The first digit represents the year, and the last three digits represent the day. Date code 7304 = 304th day of 2007. Sometimes other letters representing batch numbers will be appended to the date code (i.e. 7304C). Since the official longevity of an MRE is no longer than 10 years, and the modified date code makes it impossible to determine the decade of manufacture, this calculator assumes that your MREs are not 10 years old or more.
During WWII when hungry GI's were ready to dive into that delicious meal
of C-Rations, they used their trusty P-38s to open the cans. No it wasn't
a WWII fighter plane or a pistol, it was an amazingly simple 1-1/2 inch
stamped metal gadget that was developed by the Subsistence Research Laboratory
located in Chicago during the Summer of 1942 and unbelievably in just 30
days.
It's official designation is 'US ARMY POCKET CAN OPENER' or 'CAN OPENER,
KEY TYPE', but is known more commonly by its nickname which it supposedly
acquired from the 38 punctures required to open a C-Ration can. It's also
known as a "John Wayne" by many because the story goes is that
he demonstrated using them in a WWII training film, so when soldiers would
ask for one if they forgot the name they would ask for a "John Wayne".
Originally they came in individual paper packets with the directions how
to use printed on it, and about a dozen came packed with a case of C-Rations.
Unopened Vietnam era vintage P-38s still in their original paper wrapper
are hard to find so if you find one resist the temptation to open it.
These handy little gadgets have adorned dog tag chains and key rings ever
since.
