The chronology of the events documented by "Press Gang" is not immediately obvious. However, it can be calculated and the events fit together very neatly. This article simply aims to summarise the main dates, together with justifications for how we arrived at these conclusions. Some events can be dated fairly precisely; all we know about others is the year.

General Points

At some point during her time at school, Lynda skipped a school year and is now in an acadamic year ahead of where she would normally be (an occasional practice for very able pupils).
Lynda says she is 16 in Going Back To Jasper Street?, when students in the upper sixth form are normally 17 or 18 when they leave school.

The Early Years

Early 1970: James Thomson and Katherine Hill (Spike's parents) meet at Aragon High School in California.
21 years prior to Day Dreams. It must be towards the start of the year, since Spike is born in September. Even then he arrives very quickly, perhaps due to his father being drafed to take part in the Vietnam war (from a photograph seen in Love And War we know that he was in the army).

September 1970: James "Spike" Thomson II is born in New York City.
Spike celebrates his birthday in Head And Heart, which appears to be at the beginning of a school year. His year of birth has to be 1970 for him to be in the right school year, assuming that he has not skipped a year like Lynda (which I think is a pretty safe bet given Spike's time at school prior to the Junior Gazette). His place of birth is given in Interface.

1971: Michael Eliot is born
He was 15 when he died two years prior to How To Make A Killing.

Late March 1971: Kenny Philips is born.
Kenny's star sign is Aries according to Breakfast At Czar's and Colin is said to be eight months early for his birthday in Rock Solid which takes place in July (see later). He would have been born in 1971 in order to be in the right academic year, assuming that he hasn't skipped a year in the same way as Lynda. In How To Make A Killing, Kenny says that he met Lynda 12 years ago when he was 5.

Late August 1972: Lynda Day is born.
Lynda says she is 16 in Going Back To Jasper Street?, which is dated to April 1989 (see later). She says that her star sign is Virgo in Breakfast at Czar's. However, if her birthday was in early September she would have already have had her birthday before Going Back To Jasper Street? and so would be two academic years younger than the other characters, which is unlikely. (An explanation: in the UK August/September defines the break in how a child's birthday determines which school year they will be in, with the oldest in a particular year having their birthday in September and the youngest in August).

Late 1972: Benjamin Drexil is born.
He is sixteen and a half in Something Terrible.

September 1976: Lynda and Kenny meet.
Twelve years before How To Make A Killing. Kenny is 5 at the time, and it seems logical to suggest that it was at the start of a school year, when Lynda starts school.

November or December 1976: Toni (Tiddler) Tildesley is born.
Tiddler's year of birth is speculation, assuming that she is 12 when she joins the Junior Gazette in One Easy Lesson. This is based on the fact that she is the second year at Norbridge High at this time, due to the fact that she is said to be top at English in the lower school. British schools are often divided into lower and upper schools, with the former encompassing the first and second years. Tiddler can't be in the first year since there is then no time for her to establish this record since One Easy Lesson takes place near the start of the school year. Her month of birth is based on this assumption and that she gives her star sign as Sagittarius in Breakfast At Czar's.

1974 onwards: Spike's parents frequently separate but are reconciled on each occasion.
Referred to during A Night In (Spike was 4 when this started).

1976 to 1977: Cindy Watkins, Laura Wilmott and Sophie Jenkins are all born.
Cindy is a first year at Norbridge High in Something Terrible. Putting Sophie and Laura into the same year is an assumption based on the fact that Colin asks them to find something out about her.

1978: Chrissy Stuart becomes a reporter.
Chrissy's notebooks are seen to go back ten years in How To Make A Killing

Summer 1978: Lynda over-reacts at the school sports day after losing the egg and spoon race to a girl called Suzy Bennett.
Ten years prior to How To Make A Killing.

Late March 1979: Lynda runs off on Kenny's birthday and gets lost. She later reappears with a strange wooden carving.
Flashbacks seen in Going Back To Jasper Street, ten years prior to the main action.

1980: Katherine Hill leaves Spike and his father for good.
11 years prior to Day Dreams.

1981: The popular television series "Colonel X" finishes when its star, John England, is apparently killed in a car accident.
In UnXpected Frazz is researching an article to coincide with the tenth anniversary of the show finishing.

1981 or 1982: While in her last year at primary school Lynda sprains her arm when she tries to push Kenny out of a window.
Mentioned in Something Terrible.

1982 or 1983: While in her first year at Norbridge High Lynda writes an embarrassing story called "The Fluffy-Wuffies And The Silly-Billies".
Mentioned in The Week And Pizza.

1984: Spike moves to Norbridge. For his birthday this year he receives a present of a watch from his Aunt which he is still wearing at the time the Junior Gazette starts.
Spike's move to Britain is four years prior to Page One. The origins of his watch are mentioned in A Night In.

1985: Malcolm Bullivant is expelled from Norbridge High for vandalising the headmaster's car.
Four years prior to Something Terrible.

1986: Billy Homer is paralysed after he is knocked off his bike by a bus.
This is a complete guess! However, in Interface it is mentioned that Spike knew Billy before his accident, so it must be after 1984.

12 December 1986: Michael Eliot dies when he attempts to fly from Highpoint Flats under the influence of the glue that he has been sniffing.
Kenny first observes Jenny Eliot on the second anniversary of her brother's death in How To Make A Killing.

1987: Frazz is sick on Spike's living room carpet.
Two years prior to Something Terrible.

The School Years

Spring 1988: Lynda and Sarah are caught in their activities producing "Damn Magazine". Matt Kerr moves to Norbridge and starts planning the Junior Gazette with Bill Sullivan and Timothy Winters, inspired by an article in Lynda's magazine. Spike is suspended from school.
Seen as a flashback in Friendly Fire. It is not explicitly dated, but it is implied that there have been 8 issues of "Damn Magazine", and this date leaves time for the Junior gazette to be planned over the Summer. Julie also confirms that the characters are in the sixth form. Spike's suspension is mentioned in Page One.

Summer 1988: Preparations for the start of the Junior Gazette. Lynda is appointed editor over Sarah, who failed the interview. Most of the team start to join.
Extrapolating events. Sarah's failure to become editor is mentioned in Friends Like These.

September 1988: The Junior Gazette starts. Spike is forced to join tha paper. The events of Page One, Photo Finish and One Easy Lesson. Tiddler joins the paper.
The Junior Gazette is said to be 9 months old in Friends Like These, which is explicitly dated (see latter). Page One is also at the start of a school year. Photo Finish takes place days later (on a Saturday). One Easy Lesson is also near the start of a school year since Mr Knowles has just begun teaching and is having no success, and the Junior Gazette is still recruiting staff.

October 1988: Deadline, A Night In.
The paper is also young in Deadline since there isn't much in the Rainy Day File. A Night In is also still early, since Lynda's threat to have Spike bounced implies he has not been at the paper long enough to establish much of a record. If late duty is assigned once a month, and Spike has not yet had one as this episode begins, it may still be September.

Late October - November 1988: Interface.
Some time has passed since the paper started and people on the news team are starting to move into their permanent roles. The episode covers five weeks, as the writing contest that it concerns has not yet closed when the story begins. Billy Homer's first television review is of The Ruth Rendell Mystery "A Guilty Thing Surprised", which aired in late June 1988, so this must be a re-run that he is writing about (in reality the episode would have been in production at about the time of its original run).

12 December 1988 to January 1989: How To Make A Killing and How To Make A Killing Part Two. Kenny starts going out with Jenny Eliot
The date is established in the story, since Jenny Eliot draws her brother's outline on the pavement on the 12th day of each month, the anniversary of his death. Kenny first observes her on 12 December and engineers a meeting with her on 12 January. In the first episode, Frazz says that he has been with the paper 6 months, but he seems to be talking about his involvement prior to working on the first issue.

January 1989: Bobby Tweed arrives at Norbridge High.
Two months prior to Money, Love And Birdseed.

February 1989: Both Sides Of The Paper.
The episode concerns the character's taking their mock exams (A-Levels), and takes place over a month; it starts two weeks before the exams, which themselves take a fortnight.

Early - Mid March 1989: Money, Love And Birdseed, Monday-Tuesday and Shouldn't I Be Taller? Julie leaves the Junior Gazette to go to art college. Sam Black joins the paper as the new head of the graphics department. Danny McColl also leaves and Kevin takes over as photographer.
Exams have now finished and the pigeons have appeared. Monday-Tuesday takes place over two days (obviously), with Shouldn't I Be Taller? over a slightly longer period of time (perhaps one or two weeks). Julie has left by the time of Breakfast At Czar's. She has been gone two months by the time of Friends Like These (her fate is mentioned in the third "Press Gang" novel, perhaps implying that her mock exams did not go well). Sam has been with the paper two weeks by the time of Breakfast At Czar's.

Late March 1989: Breakfast At Czar's, Picking Up The Pieces. Kenny is dumped by Jenny Eliot.
Jenny dumps Kenny in Picking Up The Pieces, which takes place over two weeks since this is the length of time that Spike is suspended for (he is the fourth Junior Gazette person to be in trouble that month, implying that it is towards the end of the month).

Early April 1989: Going Back To Jasper Street, The Week And Pizza.
Going Back To Jasper Street follows on from Picking Up The Pieces since Kenny is still mourning Jenny. The Week And Pizza takes place over...erm...a week.

Mid to Late April 1989: Love And The Junior Gazette, At Last A Dragon, Something Terrible, Something Terrible Part Two. Spike and Lynda begin their relationship.
Love And The Junior Gazette takes place over two days. In this episode Kenny says that he met Jenny Eliot about three months previously. In At Last A Dragon Colin says that they will all be leaving school in a few months. Something Terrible opens four days later. According to Lynda, the events of Shouldn't I Be Taller? happened "a few months ago".

3 May 1989: Friends Like These.
This episode can be dated exactly since it takes place on the day after Jason Wood's concert in London. According to the poster at Norbridge station this was on Tuesday 2 May. The day of the week confirms that the year is 1989.

May 1989: The Rest Of My Life.
The episode covers one day.

June 1989: Yesterday's News. Spike and Lynda split up.
Spike has been in hospital for two weeks.

July 1989: Rock Solid, The Big Finish? The team leave school with the future of the Junior Gazette uncertain. Spike leaves for America.
Rock Solid takes place over at least two days. Colin indicates that they will be leaving school in two weeks. The Big Finish is then probably set during the last week of term, starting on the Monday and finishing with Kenny's concert on the Friday.

The Professional Years

January 1990: Spike returns to Norbridge. The Big Hello, Killer On The Line.
The Big Hello is six months after The Big Finish?, since it has been this long since Spike and Lynda last talked. The episode takes place on a Saturday. Killer On The Line also takes place on a Saturday, starting at 9.55pm. Spike refers to "the lessons we covered last year" when talking to Sarah; this refers to her assertiveness training in How To Make A Killing which would have been in January 1989.

Between January and April 1990: Chance Is A Fine Thing.
The episode covers at least four days.

24 April 1990 and several days afterwards: The Last Word, The Last Word Part Two.
The siege begins shortly after 9am on the 24th, according a news report.

May 1990: Holding On. Spike goes back to America.
Zoe has not seen Spike for "weeks". It appears to have been several months since The Big Hello.

Late 1990: Kenny emigrates to Australia.
No actual dating available, other than the fact that it occurs between Holding On and Bad News.

First six months of 1991: Spike returns to Norbridge again. Bad News, UnXpected, She's Got It Taped, Love And War, In The Picture, Day Dreams.
There is no actual dating available for series four; it's simply a matter of fitting it between episodes that we have information for. Also, there is a poster for the movie "Paper Mask" (which was released in 1991) in Colin's office in UnXpected.

Early September 1991: Head And Heart.
It appears to be the start of a new school year, and Frazz says that they left school two years previously. Some time has elapsed since Day Dreams as Spike and Lynda are comfortably in a relationship.

September 1991: Friendly Fire. Lynda fires Sarah so that she can go to university.
The university year starts in October.

Late 1991: A Quarter To Midnight, Food Love And Insecurity, Windfall, There Are Crocodile.
No explicit dating available.

2005: Lynda becomes editor of the Daily Chronicle.
According to Spike's dream in Holding On, anyway.