Amazon is testing a new delivery service that breaks the day into 10 distinct windows spanning 24 hours. The company is conducting a small pilot in a few U.S. locations to test the delivery structure that will introduce shorter delivery windows and provide customers with more frequent delivery options throughout the day, according to a spokesperson.

The new 10-window delivery structure turns delivery into an all-day cycle with faster options carrying premium fees. Under the new system, Amazon divides the day into named, overlapping windows, each roughly three hours long, according to internal documents.

The windows span early-morning slots like 3 a.m. to 6 a.m. through evening and overnight periods such as 8 p.m. to 11 p.m. and 11 p.m. to 4 a.m., according to internal documents. The windows have internal codenames such as "Sunrise," "Coffee," and "Nightowl."

Amazon has explored charging extra fees for fast delivery options, including 45-minute and 2.5-hour services, according to internal documents. The company wants to show customers specific arrival times instead of a range of delivery windows, according to internal documents.

"We are always innovating on behalf of customers and continue to find new ways of offering them lower prices, greater selection, and more convenience," a spokesperson said. Amazon is not moving to exact, minute-by-minute scheduling, the spokesperson said.

The initiative began as a pilot program with plans to potentially expand across the network later this year, according to internal documents. Amazon has not decided on the future rollout of the new delivery program and is evaluating customer response before deciding whether to expand it broadly, according to a spokesperson.

A cost estimate based on expanding the all-day delivery service to all sites by July projects costs of more than $330 million this year and over $780 million next year, according to internal documents. A slower rollout reaching full scale by September 2026 would bring next year's costs to around $490 million.

Amazon internally projects that the new delivery fees and higher sales volume will make faster shipping a profit driver even as it expects hundreds of millions of dollars in near-term costs, according to internal documents. The company expects premium delivery fees to generate at least $20 million in incremental revenue this year.