Caroline O'Connell was en route to a friend's Old Lyme beach house on Sunday when she and her husband experienced a momentary panic.

They had forgotten to pack their hospitality gift, a bottle of wine.

If this were any previous Memorial Day weekend, the O'Connells would have had limited choices. They might have backtracked home to central Connecticut, detoured through Rhode Island - where liquor stores are open all week - or been the guests who showed up empty-handed.

But this year, they had the option of a better Plan B: a visit to Rooneys Package Store on Shore Road, near their weekend destination. The liquor store was one of many across the region and state that decided to open this holiday weekend, and business looked steady at mid-day when O'Connell dashed inside.

"To be able to get to the package store on Sunday, the convenience factor is big," said fellow customer Sean Vokey, 30, of Manchester, also in town for a beach house party.

This weekend marked the second weekend since Connecticut lifted its longstanding ban on the Sunday retail sale of alcohol, and the first Memorial Day that package stores and grocery beer aisles were not forced to close.

(They may now also do business on the Fourth of July, Labor Day and the Monday following Sunday holidays. However, it remains illegal to sell alcohol on Thanksgiving, Christmas and New Year's Day.)

For consumers, the lifted prohibition is proving hugely popular. "Everyone walks in and says they're so happy we're open on a Sunday," said shop worker Mary Lou Raschello of The Packy on Bank Street in New London.

But among package store owners, the reviews thus far are mixed. Some have noticed an overall uptick in business, particularly for stores near marinas, beaches and tourist areas. Yet others, such as Susan Kumro of Mermaid Liquors on Main Street in Niantic, aren't sure whether the sales revenue from Sundays and the holiday will be enough to justify the added overhead expenses.

"I'm going to predict that there's not going to be any difference, except for my electric bill," Kumro said about this year's and last year's holiday weekend, pointing to her beer coolers going full blast. "It's the same customer that would usually come through here Saturday night."

Under the new law, Sunday alcohol sales are permitted from 10 a.m. to 5 p.m., although businesses aren't required to open. State officials are anticipating $5.2 million in additional yearly state revenue as a result of the added sales day.

Jamison Shaw, 30, a New York resident visiting family in his hometown of Niantic this weekend, said he made beer and wine purchases Sunday that he maybe wouldn't have made if package stores had been closed.

"We went through most of what we had last night, and we are fortunate that there's more" available, he said.

Closer to the Rhode Island border, Universal Package Store in Noank was doing swift business Sunday afternoon. Co-owner Mike Edgerton said that many of his customers are out of state during the work week, so Sunday opens a new revenue stream and isn't just spreading six days of businesses over seven days.

"It's only two weeks, but so far it's been good," he said.

Some package stores anticipate being open on Sundays only during warm months and peak tourism season. That's the plan at Mr. P's Fine Wines and Liquors on Flanders Road in Niantic, which is following a Memorial Day weekend-through-Labor Day schedule for its Sundays.

Co-owners Joe and Nancy Trask are preparing to work seven days a week all summer. "We would normally be at the beach today," Nancy Trask said, smiling. "Now we'll be open."

But the extra labor could pay off. The Trasks spotted six cars in their store's parking lot Sunday morning, waiting for them to open shop. "A lot of people say they want to stop in just because they can," Nancy Trask said.

Diane Sullivan of Niantic was one of those customers. She could have made her purchase on Saturday but wanted to experience the novelty of buying alcohol in Connecticut on a Sunday.

As Sullivan walked out of Mr. P's with her newly purchased bottle of wine, she exclaimed, "My God, Sunday sales!"

j.reindl@theday.com