The bankrupt United States Postal Service is going to try its hand at same-day delivery, something it's hasn't done since baby boomers were tykes.

It'll be trying out what it calls Metro Post starting in mid-November in San Francisco and deliver packages between four in the afternoon and eight in the evening. The service is designed for e-commerce companies.

Consumers will be able to buy from partnered e-commerce platforms, the retail store, or from the web site of one of the companies offering the service up until 3 pm.

The post office blacked out its proposed pricing in its filing with its regulator, the Postal Regulatory Commission, which has to approve the scheme first. The trial is supposed to help the USPS figure out what the market will bear.

It figures Metro Post could bring in $10 million or more year-one but not top $50 million a year ever.

To take part, companies must have 10 physical locations nationwide with at least one location in the test market.

The San Francisco test may last a year, and expand into additional cities. The USPS only expects to be able to handle 200 packages a day initially.

The USPS is reportedly talking to retailers and may work with 10 of them. "The product is likely to contribute to the financial stability of the Postal Service by generating more package deliveries that do not currently move within the postal system," the agency said in the filing.

Deep in debt, the USPS is trying to cut $20 billion in yearly operating expenses by 2015 to stay alive.