Comedian Marina Franklin would normally be offended if somebody fell asleep during her stand-up routine, but 13 hours into a 50-hour comedy marathon she's willing to cut the crowd some slack.

Franklin was one of around 100 comedians trying to set a Guinness world record for the longest non-stop stand-up comedy show this week at a New York comedy club.

"The hardest thing is to make people laugh when they're tired," Franklin told Reuters after coming off stage on Wednesday morning, her second set during the 50-hour marathon that started on Tuesday night.

At one point as she told anecdotes about her cat, she turned to a woman whose head was sinking to the table in the dimly lit Comic Strip Live club, where about 25 people were enjoying comedy over breakfast.

"Get her up," Franklin told the woman's friend, but she didn't give her any serious abuse.

The woman in question was Elinor Naor, a 19-year-old student from Baltimore, who said she had been up most of the night at the show. She slipped out after Franklin's set to take a short nap in her car, promising to come back.

"I feel bad falling asleep," she said on her way out.

The comedians were donating their time to raise money for the Intrepid Fallen Heroes Fund, which helps wounded military personnel and the families of those killed, mostly in the wars in Iraq and Afghanistan.

William Stephenson, who emceed the show and promised to stay awake all 50 hours, said the hardest time was 6 a.m..

"That's just not a time for comedy. Either you've been up all night and you're tired or you've got up too early and you're tired," he told Reuters.

But he said the crowd had been pretty good even at that time on Wednesday, helped by a group who stayed for 12 hours from the start on Tuesday evening.

"The mood was reserved, but there was still some life in the audience, which surprised me. Two hours is generally the maximum time a comedy show will go before the energy just leaves completely," he said.

Comedian Pete Dominic told the crowd he'd been offered the best time slot but he'd asked to be there at 10:30 a.m.

"I don't know why you people are here, but it's awesome," he said. "I think it's awesome that you don't have jobs."

Kristi Bethel, a middle-aged office manager from Nebraska, sat in the back of the club with three friends visiting New York.

"We wanted to do something you can't do in Omaha," she said.