The biggest online shopping day of the year, known as Cyber Monday, will begin this year at 8 PM EST on Sunday night, according to a report on Reuters.

The world’s largest retailer, Walmart, announced it would begin to offer its online Cyber Monday sales on Sunday night instead of the early hours of Monday morning as had been done it the past several years.

The retail industry expects sales for the event to reach around $3 billion this in the United States year, a 12 percent increase from the previous year and likely will set a new record for Cyber Monday sales.  The online event is the largest single day of online revenue of the year, but this year, sales on Black Friday, the day after Thanksgiving, are also expected to rise 15 percent to somewhat close the gap.

Cyber Monday began over ten years ago when people started using online shopping to make their Christmas purchases and avoiding the large crowds and problems with actually going to brick and mortar stores for gift shopping.

The original concept was that consumers would have access to high-speed internet at their work place and would do shopping there as opposed to their often slower connections at home.  Now with widespread use of smartphones and tablets, online shopping can be done from almost anywhere.

Fernando Madeira, chief executive of Walmart, said since high-speed internet is now readily available across the country, the logic of holding the online sales event to just one day no longer rings true.  He added the customers have changed, but the event had not changed with them.

Last year, Walmart made some 500 Cyber Monday deals available on the Sunday after Thanksgiving, but the company plans to release all 2,000 online special deals for this shopping season on Sunday night.

All this is part of a battle brewing between online marketers and Amazon, which is several times larger than Walmart with regard to e-commerce, and is growing at a faster rate as well.