In this segment, hosted by Kang Ho Dong, the members go on an overnight trip to various places of interest in Korea. The aim of the segment is to recommend holiday destinations to its viewers. Often the members are accompanied by a dog nicknamed "Sang Geun". His real name is Herbie but was nicknamed "Sang Geun" by Ji Sang Ryul. Sang Geun is a Great Pyrenees whose popularity grew hugely in the first half of 2008 partly due to the show. Throughout the show, there are several mini-games played to see who will eat dinner (as opposed to a simple snack), who will do the chores or work that needs to be done, and who will sleep comfortably. The segment's cast includes entertainer Eun Ji Won and comedian Lee Su Geun; recent additions include singers Kim C and Lee Seung Gi and rapper MC Mong. Former members include Kim Jong Min, Ji Sang Ryul, and Noh Hong-cheol.
Former member, Kim Jong Min had to leave the show because he started his mandatory military service in November of 2007, while No Hong Chul left the show due to exhaustion. No Hong Chul now appears on SBS's Good Sunday line-up in the segment Change.
Each member has a nickname which represents their character or appearance. Kang Ho Dong is usually called "pig" (돼지) or "bear" (곰) because of his size. And "Janggiyeppff" (장기예프), because his scrawl. MC Mong is called "wild monkey" (야생 원숭이), because of his appearance and actions. Eun Ji Won is named "elementary kid Eun" (은초딩) or "kid" (아이) because of his childish behavior or way of thinking on the show. Lee Su Geun is named "worker" (일꾼) because he is so good at doing work like building, cooking, chopping up wood for the fire, etc. Kim C has sometimes been known as being an "expert" (달인) at something and also as the "big brother" (큰형) because of his care for the younger cast members on the show. Lee Seung Gi's nickname is "Huh Dang" (허당) which means a person who is just a little bit odd in his or her way of thinking or someone who doesn't quite understand something the first time something is said.
The cast members have taken various trips throughout Korea, including many nearby islands. The most notable trip to date has been to the Dokdo, controversial due to the ownership claims of both South Korea and Japan. On their 17th trip to Wando County in South Jeolla, the cast was told to live and experience the wildlife having no access to their cellphones and having to build a tent on their own with the given materials. In June 2008, they travelled to Baekdu Mountain (백두산) which is located on the border of North Korea and China. The trip took 4 nights and 5 days, rather than 1 night and 2 days. They took the scenic route to Baekdu Mountain by taking a boat to China than taking a bus to the actual mountain rather than taking a direct flight in order to film the beautiful scenery along the way. After climbing up the stairs leading up the mountain they reached Heaven Lake (천지, 天池), one of the highest crater lakes in the world. At Heaven Lake they symbolically poured water from Liancourt Rocks (독도), the disputed easternmost island of Korea; Udo (Jeju) (우도), one of the southernmost islands of Korea; Gageodo (가거도), the westernmost island of Korea; and Baengnyeong Island (백령도), the northernmost island of the West Sea. This was to symbolize their wish for Korea to once again become one united nation just as the waters became one at Heaven Lake.
Singer and actor Lee Ji Hoon was offered to join the cast of 1 Night 2 Days but rejected on two different occasions. Lee Ji Hoon was asked: "1 Night 2 Days makes you jealous right?" on an episode of KBS Sang Sang Plus Season 2 which aired May 27, 2008. He said he was jealous and further explained that he was very close with one of the producers of 1 Night 2 Days as he has worked with him before. He rejected the offer and chose to take a role on MBC's drama New Heart instead. The role he was given was as a celebrity, which ended up not fitting into the drama's storyline. His character was later removed from the plot. He rejected his second offer for his new drama You Are My Destiny.
On December 27, 2008 at the 2008 KBS Entertainment Awards, all six cast members were present at the award show. The members performed "No Matter What" by Park Sang Chul. Happy Sunday: 1 Night 2 Days took home five awards - Best New Variety Show MC Male Award, Best Screenwriter, Best Popular Award, Audience's Best Producer (Program) Award, and the Grand Award (Daesang). In the Best Popular Award category, three out of the four nominees were from 1 Night 2 Days - Eun Ji Won, MC Mong, and Lee Seung Gi, where Lee Seung Gi won the award. The Audience's Best Producer (Program) Award was based on viewers votes through surveys and SMS. Happy Sunday ended up with 108.3% of the votes, and trailing behind them with 40.3% of the votes was Happy Together (Gag Concert with 33.1% of votes, A Chat with Beauties with 12.9% of the votes and Sang Sang Plus with 5.3% of the votes). According to TNS Media Korea, the 2008 KBS Entertainment Awards Part 2 was the first in ratings in Seoul and nationwide for December 27 - ratings of 28.3% nationwide and 28.1% in Seoul. 2008 KBS Entertainment Awards Part 1 placed fourth with 20.8% nationwide and 21.2% in Seoul