Black Friday — the US retail phenomenon that prompts bargain-hungry shoppers to stampede through stores — is coming to South Australia for the first time.

Key points: Adelaide retailers will be able to trade until midnight on November 29

Adelaide retailers will be able to trade until midnight on November 29 Treasurer Rob Lucas says it will allow bargain-hunters to kickstart their Christmas shopping

Treasurer Rob Lucas says it will allow bargain-hunters to kickstart their Christmas shopping He will announce next month if there will be extended trading over the Christmas period

Adelaide retailers will be allowed to open their doors until midnight on November 29.

Treasurer Rob Lucas used his ministerial discretion to allow extended shopping hours for one day only, which will coincide with popular Black Friday trading across the world.

He granted the exemption to allow bargain-hunters to "shop 'til they drop" and get a head-start on their Christmas shopping.

"We know there is an enormous groundswell of public support for extended shop trading in South Australia and the burgeoning popularity of Black Friday sales here is a fantastic opportunity for consumers, retailers and employees alike to capitalise on that demand,'' he said.

"This will be a welcome shot in the arm for local bricks and mortar businesses as they compete with the rapid rise in online sales.

"The Government wants to continue to drive positive economic and jobs growth, and this move — while entirely optional for retailers and their staff — will generate additional sales while creating valuable employment opportunities for those people who'd like to work."

Westfield Shopping Centre at Marion will trade until midnight on Black Friday, while many traders in Rundle Mall will also open.

Major department stores David Jones, Myer, Harris Scarfe, Kmart and Big W, as well as Sephora and H&M, have all indicated their support for the Black Friday midnight trade.

Online trade hurting retail stores, workers say

Westfield Shopping Centres at West Lakes and Tea Tree Plaza will open their doors until 9:00pm.

"Black Friday" — an informal name for the Friday following Thanksgiving in the US — has been the unofficial start to the country's shopping season since 1952.

Marion Shopping Centre retail worker Chris Stewart said in his experience, extended trade could be "a bit hit or miss", especially with online shopping.

"I'm worried we won't see anyone past 9:00 or 10:00pm but we'll see how we go — we've got pretty good sales on," he said.

"Having to work extra hours does put us out a bit."

Marion Shopping Centre retail workers Talia Goodliffe and Chris Stewart. ( ABC News: Brittany Evins )

Talia Goodliffe said advertising about the extended Black Friday trading hours was needed.

"It's really online focused these days, even over Christmas, people aren't coming in as much because people would much rather stay at home and order their stuff online," she said.

"Black Friday is more of an American thing so people buy off the American sites — it's not really an Australian thing. It's going to be a good trial to see how it goes."

Small businesses not opposed to Black Friday

South Australian Independent Retailers chief executive Colin Shearing said he was not opposed to the extended Black Friday hours because it was aimed at "big box" purchases such as televisions and electrical goods.

"We're saying it doesn't affect the smaller businesses, especially food and grocery," he said.

"It gives an opportunity to those retailers who are looking to, I guess, use their Black Friday which is like another sales day for them and it doesn't really affect supermarkets or small business."

Last year, Mr Lucas granted a special exemption for shops in Adelaide's suburbs to open from 9:00am to 5:00pm on Boxing Day in a first for SA.

The Treasurer described the Boxing Day trade as "a roaring success".

But Mr Shearing was against the move.

"Extending hours over the Christmas period is only sensible and we're saying this gives all consumers the opportunity to shop at different hours for those with a busy life over Christmas," he said.

"But we oppose any opening up of public holidays so we oppose the opening up of Boxing Day, which has been suggested."

Black Friday staff must volunteer to work

Mr Lucas said no staff would be forced to work the additional hours on Black Friday.

"To reinforce this, the exemption — which is the same that has been used in previous years and for Boxing Day last year — contains a condition that all employees working during the extended hours will do so on a strictly voluntary basis," he said.

Mr Lucas said he would make a decision in the next month in relation to whether any additional shop trading exemptions would be granted over the Christmas period.