Brad Pitt forgot to celebrate Thanksgiving because his young family was elsewhere.

The 'Killing Them Softly' star revealed he unintentionally skipped the US holiday on Thursday (22.11.12) because his fiancee Angelina Jolie and their six children - Maddox, 11, Pax, eight, Zahara, seven, Shiloh, six, and four-year-old twins Knox and Vivienne - were in Cambodia while he was in London filming his new movie.

The 48-year-old actor told People magazine: "I didn't know it was Thanksgiving until like midday. Until [the] afternoon.

"When you're overseas, they don't celebrate it in England. And [Angelina Jolie] and some of the kids are overseas in Cambodia this week, working on the [The Maddox Jolie-Pitt Foundation] there. It completely escaped me until someone brought me some English pumpkin pie."

But the actor admitted he wasn't upset about missing out on the annual holiday.

He said: "That's okay, last year we had a big meal and we don't normally miss things twice."

But despite forgetting about the holiday, the actor thrilled one English family with his generosity over the weekend.

He donated $1,100 to a fundraiser collecting money for the Southampton General Hospital's neonatal unit, where a friend's baby boy, Zachary Gallagher, had spent the first nine weeks of his life.

The baby's mother Karley Gallagher, 23, said: "The fundraiser had finished, and I got a phone call from my best friend, who said, 'We have had a small donation.' I thought she was messing about and was going to say, 'My dad's given you a fiver' or something, then she said, 'It's from Brad Pitt!'

"He said that he had seen the fundraiser mentioned in the local papers and seen my fliers and thought it was a really great cause and was just sorry he couldn't have been there.

"The silver lining is that Zachary is home and alive. ... To have Brad assist us is more than we could ever have wished for."