Timeline and References in Episodes

Most series that deal with real past times don't go for exact accuracy and play around as closely as possible with things that can be relevant among historic/pop-culture/cultural events/available props. 

Timeline in the episodes : 

In Ep 1-3 the calendars are set to March, in Ep 4 its April, Episode 6 it is June, Episode 7 on July.

Episode 1 (March)

• The national assembly elections being talked of since Ep 1-3 were held on 25 March 1992. The Presidential elections will be held on December 18th 1992.
  • The posters for the election seen are for candidates from places of North Jeolla in the 1992 election
  • A poster for Daejeon Expo 1993 is also seen
  • North Jeolla is historically famous for it's Gochujang(chilli pepper paste)
  • A regional Miss Gochujang beauty contest exists
• The toy whose eyes Jeong-suk sews is "Dooly the Little Dinosaur" (1983)
• The beginning of elementary school which would be in first week of March 1992
  • The children entering should be 7/8 years
  •  Yong-bok's 3rd daughter is in class 2. Min-ho and Dong-u were standing in line for class 3
• Min-ho's hand-me-down backpack from his cousin has the titular character from "Magical Princess Minky Momo" (1980s) on it.
• Errata: the calendar in the butcher's shop has March as title but the dates are for February 1992, a leap year. 
  • later on  in the scene detective Na barges in on Joo-ri changing too the calendar shows heading March but dates are for April '92
• From Han Jeong-suk's resume she is 31 (17/8/'61) and she graduated elementary/middle/high school in '74/'77/'80. Her rrn seems to have North Jeolla code place of birth. 
• The date for the Fantasy Lingerie job information session is given as March 4th, 10a.m. in the newspaper advertisement
• Mrs Kim gives a general global history of sex toys
  • 1880s: origin of vibrators- the pop story about Dr Joseph Granville and hysteria treatment
  • 1960s: stores in US openly start selling sex toys
  • 1977: first Good Vibrations store opens in San Fransisco
• According to Mrs Kim(Ra Mi-ran)'s story she'd have started her business in 1980s
  • the US army garrison(Camp 'Hampiraus') she is shown in- it is shown as being located in Geumje on it's board
  • the regional building they are using has a logo also seen later on house nameplates - Geumje Saemaeul Women's Association.
• Silence of the Lambs (Jun 1991)

Episode 2 (March)

• Joo-ri and Dong-u are watching fireworks for Daejeon Expo '93 celebration event on TV (one such notable event was held in 1991) 
• The song Uhm Dae-geun sings is Shin Seung-hun's "Don't Make me Cry"
• Epilogue charts out personal details of majority of Geumje resident's(main and recurring characters) personal details on Do-hyeon's Evidence Wall

Episode 3 (March)

• When questioned about when the rice seller bought the spray paint the hardware store owners talk of Animal Quiz Show with Son Bom-soo at 7-8pm slot. Son Bom-soo actually started on the show from Apr 9, 1992 according to wikipedia and he became well known for it. 
  • The calendar in their shop has the heading March but the dates are actually for April 1992 
• The action figure Min-ho receives is Kangnam Model's King Lion (GoLion/Voltron)
• Mi-hwa's birthday party where Jeong-suk ends up having to do sales 
  • Mi-hwa's birthdate as well as surname were written wrong on Do-hyeon's evidence wall(her surname was written same as her husband's Park, instead of her own- Seong)
• The movie Min-ho goes to watch is Young-Gu and Daeng-Chil 4 (1991)
• Jeong-suk had marked March 31 as payday on her calendar
• Jeong-suk's mother(born 1935) would have been 32(korean age?) around 1966 ('65-'67) which would be when the backstory is set

Episode 4 (April)

• The kids in the video rental store try to chose between Ureme 6 (1989) and Super Hong Kil-Dong 3 (1989). Both released on video in 1990 a month apart respectively
• The Lotte traffic light candy/negeoli candy has been discontinued and re-continued since1990s
  
• Shim Shin. Song Joo-ri hums is "You Are The Only One" (1991)
• Ep 4 ending- the famous Seo Taiji and the Boys TV broadcast was on April 11, 1992 and is thought to be their debut(which had actually occured earlier)

Episode 5 (April)

• The kids are playing Street Fighter II (1991) in the convenience store's arcade machines (Dhalsim vs Chun Li)
• Papers possibly related to Do-hyeon's orphanage and adoption are seen but the dates are covered. He might have been adopted in 1963. 
• Seong Mi-hwa has a checkup that day and is given the news she is 6 weeks pregnant
• In-tae and Mi-hwa have been married for 8 years
• Cold case files related to the arson and kidnapping are seen with dates in 1962 and 1963. 
• The song Dae-gun sings along to is Shim Shin's "You Are The Only One" which he has put on endless repeat
• The song in the background of Won-bong's fantasy dance is Shim Shin's "Greedy Person" (1991)
• Min-ho draws a family drawing from their time going to Lake Soyang(famous spot in Chuncheon)

Episode 6 (June-July)

• Jeong-suk and Seong-su finally get divorced on an unknown date in June
• Next day the gang heads to an overnight trip to 'Gyesim-do'
• Kim Wan-sun; Park Nam-jung
• Jeong-suk's mother says she lived in Geumje since around 35 years ago
• Kim Hye-soo's Thirsty Hippo commercials (1990) 
• Sex fantasy scenarios parody - Titanic (1997; Feb 1998) and Basic Instinct (May 1992)
• After returning from the trip when Jeong-suk is thanking Do-hyeon for looking after Min-ho the calendar in the background is now July 1992
• Joo-ri told the older customer he resembles Chow Yun-fat and styled him for the iconic look with a matchstick in mouth(in A Better Tomorrow)
• Joo-ri can't recall who Dae-geun was supposed to resemble and at the prompting she exclaims Shin Soo-bong
• According to subtitles Yeong-bok asks for freedom pad (possibly Yuhan Kimberly's new freedom)

Episode 7 (July)

• Min-ho and are Dong-u playing the Diamond Game
• Lee Man-gi is a famous ex-ssireum wrestler
• Choushinsei Flashman is the first dubbed super sentai released in Korea (1989)

Episode 8 (July)

• The movie they go to watch is Madame Aema 6
• Geum-hui and Wong-bong's wedding anniversary is on July 10th

Other References

• Han Jeong-suk's name (한 정숙) is a wordplay to mean "virtuous/quiet/dignified, etc", the same as used in the title of this KDrama (정숙한 세일즈 jeongsukhan seiljeu)
• Geumje (금제) might have fictionalized its name from some towns like Gimje(and Oksan=Iksan) in the region it is set in but 금제 itself means "taboo"
• 금제 Geumje also means goldwork. In Ep. 1 Seong-su said Seung-tak's famly were the the town's head family and in ep 8 Yeong-bok's husband's friend talks of Seung-tak's family owning the gold shop he palns to rob.
• According to the official character introduction Choi Won-bong's character was supposed to appear outwardly as if he is similar to the patriarch of the famous drama What is Love?
• According to the official character introduction Park Jong-sun is described as "Byeon Kang-soe loves Madonna".  
  • In ep 2 he tells Yeong-bok that she is sexier than the singer Madonna.  
  • Byeon Kang-soe is a character from an explicit pansori "Garujigi Taryeong" who is a layabout notorious for his libido and parodied in various media. In one version Ong-nyeo(from north- now in present day N.Korea) and Kang-soe(banished from the Southermost regions) meet somewhere in the middle in Jeolla. 
  • The couple in the drama loosely resemble the couple Byeon Kang-soe and Ong Nyeo but with Jong-sun being overly devoted to Yeong-bok and good natured, with multiple children. 
• The official character introduction for Seo Yeong-bok starts with the quote "덮어놓고 낳다보면 거지꼴을 못 면한다" which was the official Korean Family Planning slogan 1963 which roughly translated means 'If you keep having children, you will end up a beggar'

Thank you for all the research. Among all the fun facts, I especially like this one:

Han Jeong-suk's name (한 정숙) is a wordplay to mean "virtuous/quiet/dignified, etc", the same as used in the title of this KDrama (정숙한 세일즈 jeongsukhan seiljeu)