On the day that they are getting ready to leave the beach house, Monica gets stung in the foot by a jellyfish and Chandler has to pee on it to make the stinging stop. Her, Chandler and Joey vow to never speak of this to anyone. Once they return to the beach house, they see Rachel and Ross and act very weird and then they go take showers. A few scences go by and then they are back at Monica's and they are telling Pheobe, Ross, and Rachel what happened. Ross and Rachel are clearly wearing the same outfits that they were at the start of the episode, when they were still at the beach house. Chandler talks about how Joey was yelling at him when he was trying to pee on Monica and he said, "Sometimes at night, I can still hear the screams," and Joey says, "That's because sometimes I just yell through my bedroom wall" This leads me to belive that days have gone by, but Ross and Rachel are stil wearing the same clothes and have the same hair styles indicating that they had just gotten back from the beach house that day.