When you head to the supermarket, the aim of any savvy shopper is getting the most bang for your buck.

But it can be tricky to know how long you're gonna get out of your fruit and veg once you get it home.

Well, if you've ever spotted those weird codes on the wrapping of some groceries and wondered what the hell they mean, here you are.

A TikTok creator going by @financegirlbargains shared a video with their followers pointing out the supermarket code while perusing the fruit and veg aisle in Tesco.

Zooming into the packaging of some mangetout, she showed that there was no clear best before date stamped on it.

Instead, there was a two digit code, 'A3', while another had 'A6' on it.

TikTok/@financegirlbargains

Well, according to @financegirlbargains, it's a way of working out how fresh the produce is.

"Tesco staff training taught me the higher the number the fresher the produce," the TikTok creator explained.

Mind blown, right?

You're not the only one, there were plenty of her followers who couldn't believe they had missed that.

And many piled into the comments to thank @financegirlbargains for useful factoid.

One user said: "I had no idea!! Thank you for sharing.

Another chipped in: "Omg thank you for this."

"Yay, I've been wondering," put a third.

While someone else added: "The amount of times I've seen people lift up the trays to get the stuff behind is too many to count."

TikTok/@financegirlbargains

Not everyone was new to the piece of info, though.

It turns out there were plenty of people who were wise to the method.

Explaining how it works, one user said: "The letter stands for the month and the number is the date. So A = January and 6 is obviously the 6th."

So the higher the number, the later the best before date and the longer the produce will stay fresh for.

Letters A to L signify each month of the year (B is February, C is March, etc., and the numbers represent the day of the each month.

So A1 is 1 January and E26 is 26 May. Get it?

Tesco isn't alone in employing the system, other chains in the country do the same thing with their items.

As to why, one customer explained: "The aim is to reduce food waste by changing the month to letters."

While another said: "Lots of UK supermarkets are removing best by dates for fruits and vegetables to avoid food wastage."