Amazon Prime customers, those special patrons who pay a yearly fee to get free, two-day delivery, will now be able to include in the two-day count Sundays, beginning in the Los Angeles and New York City regions.

Amazon is working together with the US Postal Service to roll out this new service, with an eye to expansion into the Dallas, Houston, New Orleans and Phoenix areas during the coming year.

“If you’re an Amazon Prime member, you can order a backpack for your child on Friday and be packing it for them Sunday night,” said Dave Clark, Amazon’s vice president of worldwide operations and customer service. “We’re excited that now every day is an Amazon delivery day and we know our Prime members, who voraciously shop on Amazon, will love the additional convenience they will experience as part of this new service.”

Amazon Prime customers need not do anything additional to get delivery on Sunday. When they add their purchases to their cart the Sunday delivery day option will pop open at checkout as soon as its available in the region they are shopping from.