Tesco has found itself in a pickle over the label on one of its ready meals.
Customer Matthew Stock did not mince his words when he tweeted the supermarket asking it to explain a best before date of 20140 on a sachet of burger relish.
The chain responded saying the code on the relish included with two beef burgers was a date from the old Julian calendar, last used 350 years ago.
Translated into the more usual Gregorian calendar it is 20 May 2020.
The Julian calendar was last used in the UK in 1752, before it was replaced by the Gregorian calendar, which is the most commonly used calendar in the world.
Mr Stock bought the Tesco own label meal which contained two burgers, two buns two cheese slices and the sachet of relish.
He tweeted the supermarket, saying: "Hello there Tesco, could you please explain this expiry date please?"
Tesco customer support replied: "The date code on the relish only is the Julian date. 20140 is the 140th day. This translated into the Gregorian calendar is the 20th May 2020."
Matthew Stock tweeted back: "Are you serious? Surely that's not a legitimate way of dating products?"
A Tesco spokesman told the BBC: "The Julian date code is used by our supplier for internal traceability purposes. The standard best before date is printed on the outside of the main packaging.
"We're sorry if any of our customers got in a pickle about this and we have relished the chance to put the record straight."
All food manufacturers are legally required to stamp a best before or a use by date on their products.
Best before dates are indicators of the quality of the food item, use by dates are about their safety.
The Food Standards Agency (FSA) pointed out the date on the relish shown in the tweet was "best before end" and "is about quality not safety".
In a statement the FSA said: "The outer pack should have a use-by date or best before date, this would be the date consumers would be expected to follow for the product as a whole."
The Julian calendar was first introduced in October 1582 by Pope Gregory XIII. It is still used by some orthodox churches, including the Orthodox Church in Russia.
The Gregorian calendar has three fewer days in every 400 year period than the Julian calendar.