Lucky for us, the shiva ceremony that defines This Is Where I Leave You is a seven-day affair. That makes it really easy for us to break down the plot.
Day Zero - Judd's father, Mort Foxman, has died after a long illness. Judd has to stay at the family home for a week to fulfill the shiva mourning ceremony. The icing on the cake is that Judd's wife just left him for his boss, Wade, a few weeks earlier.
Day One - Judd attends his dad's funeral. His siblings--Wendy, Paul, and Phillip--are there with their significant others. That night, Judd learns that Penny, his college sweetheart, is working at the Foxman sporting goods store.
Day Two - Judd withdraws a bunch of money from his joint bank account with Jen. Later that day, he finally gets the courage to say hey to Penny.
Day Three - The Foxmans debate the family business at breakfast. Paul, who's been running the store, wants to buy out his siblings' shares. Phillip, the official Family Screw-Up™, wants to start working with his brother. Their argument is interrupted by Jen's sudden entrance. She tells Judd that she's pregnant with his child. Whaaa? (Also, get that DNA tested, dude.) They talk for a while and Jen heads to a local hotel. Oh yeah, and Judd gets to first base with Penny. Good work, buddy.
Day Four - It's Saturday, so the shiva is suspended while the family goes to Temple. Judd wears his dad's old coat to the service and is shocked to find marijuana in the pocket. Judd and his brothers slip away to the nearby Hebrew school but accidentally set off the fire alarm. Think that sounds crazy? Well, when Judd gets home, he has an intimate encounter with Paul's wife, Alice. Afterwards, he fights with Jen some more, goes to a movie with Penny, and consummates their newly rekindled relationship. That's what you call a busy day.
Day Five - Judd goes to a local amusement park with Penny and they have a grand old time. They're interrupted by a call from Jen—there's a problem with the baby and she's rushing to the hospital. Penny, who didn't know about the baby until now, decides to stay while Judd rushes off. The baby is okay, but Wade's entrance rudely interrupts the former couple. Later that night, Judd, Paul, and Phillip go to a local bar. After arguing with Paul, Judd ends up stumbling home alone. Halfway there, he runs into Wade. Wade tells Judd that he's leaving Jen before zipping away.
Day Six - Judd has a productive morning. First, he has a heart-to-heart with Tracy, Phillip's fiancée. She tells him that she's going to leave Phillip. After a busy shiva (and a huge revelation about Judd's mom, Hillary), Judd drives back to the home he shared with Jen. She's there. They share a tender moment and she reveals that the baby is a girl. Things seem to be looking up—at least, until Judd gets home. When he arrives, he finds Phillip on the top roof, threatening to jump. Phillip eventually agrees to come down, but he ends up slipping and falling off anyway. After everything settles, Judd drives to Penny's house to apologize and say goodbye.
Day Seven - Shiva officially ends on the morning of the seventh day. Judd tells Paul to hire Phillip, who seems to be okay after his tumble from the roof. Paul resists at first, but realizes that with their father gone, he and Judd have to care for their little brother. He relents. Judd leaves that afternoon. He ends up taking Phillip's Porsche as payback for Phillip stealing some of his money. He sets the GPS for Maine and starts driving.