A SUPERMARKET sign has baffled customers after it seemed to suggest the store was only open for six hours.

The open hours board outside of the Tesco Extra store in Broadbridge Heath, Horsham, states that the branch is open from 6am to 12pm, Monday to Saturday.

It has caused confusion among shoppers who were confused whether the store closes at midday or at midnight.

A photograph of the notice shared by ITV reporter Kit Bradshaw on Twitter has gone viral and sparked a debate over the correct way to tell the time.

In a caption alongside the photographer, Kit wrote: “Tesco has just made me doubt myself in a way that I never thought I would.

“Can we all agree that 12pm is midday and not midnight, right!?”

The tweet has now been liked more than 10,000 times and has promoted a wide range of responses.

One user wrote: “In mathematical notation using 24-hour time: AM is the half-open time period [0000, 1200).

“PM is the half-open time period [1200, 2400) = [1200, 0000 + 1 day) AM spans from midnight (INclusive) to midday (EXclusive). 12:00pm to 12:59pm is 59 minutes long, starting at midday.”

Another added: “Well I'm completely confused now?

“I was fine till I read some of the replies. Now I don't know, my brain is coming up completely blank!”

A spokesman from Tesco told ITV that the supermarket was aware of the “incorrect sign” and that they “plan to update as soon as possible.”

He told ITV: “I can confirm the store opening hours are Monday – Saturday 6am – 12am (midnight) and Sunday 10am – 4pm.”