When the Premier League and Football League fixtures for 2013-14 are announced at 9am on Wednesday, spare a thought for the individuals involved in compiling the season's schedule.

"I don't think people realise what goes into it," says the Football League fixtures officer, Paul Snellgrove. "They think names go into a hat and it's almost like a draw. Because it's so difficult to explain it's hard to keep people's attention."

A laborious process that begins four years ahead of each season, when Fifa and Uefa set out their international schedules, goes through a raft of complex stages before the final fixture list is signed off.

Presumably those trusted with deciding when supporters must travel the length of the country on a cold midweek night, or with a blasting hangover on New Year's Day, then go and shelter in a dark room for a long, long time.

Glenn Thompson of the IT company Atos Origin is the man responsible for inputting all the data into the famed "fixtures computer", but before he does so the Football League, Premier League, Football Association and the Football Supporters' Federation undergo a series of discussions alongside the clubs, starting when a draft schedule is first proposed in November of the previous year.

Most fans understand that each club is paired with another and their fixtures will usually correspond. For example, when Manchester United play a home match, Manchester City play away. The same rules apply for Everton and Liverpool, Arsenal and Tottenham and other neighbouring teams.

It is easier to pair clubs if they are in the same division, with Swansea City and Cardiff City reunited in that respect next season, and the fixture organisers work closely with police forces across England and Wales to ensure matchdays do not stretch resources too thin.

There are fixture compilation rules, such as that over a course of five matches a club must have no more than three home or away games. If a team plays at home on Boxing Day it must travel on New Year's Day and vice versa.

Organisers try to schedule midweek matches in "good weather periods" and attempt to give clubs a home match either before of after an FA Cup tie, so as to avoid three successive away games and tricky financial situations for lower-league sides.

However, things can easily become complicated and changing one fixture has a series of knock-on effects to other games on the calendar. Policing, transport and requests from clubs make scheduling an incredibly detailed and tedious task.

For example, Greater Manchester police has to consider eight clubs on their patch each weekend. Four must play home and four away, yet there is also the fact that Bury request that they play home games when Manchester United are not in action so as to boost their attendance.

GMP also has to avoid potentially fiery fixtures when events such as the Conservative Party conference and Gay Pride weekend are in town. The Premier League and Football League also try to avoid big games on the opening day of the season and on occasions such as Boxing Day and New Year's Day.

The draft schedule is tweaked and sent out to all clubs in March, with a form asking them to respond with any specific requests. "It's very rare that we get a blank form back," admits Snellgrove, but not all can be accommodated - Birmingham City asked if they could have a home game next season on 19 April to celebrate Trevor Francis's birthday but the League could sadly not oblige, although the schedule does take into consideration the Nottingham Goose Fair and the Shrewsbury Flower Show.

"Glenn does a lot of prep work manually and will feed it into the computer," says Snellgrove. "Each club gets a space on a grid which dictates their home and away sequence. He splits the season into sections, mini-leagues, the season is basically a set of 10 mini-leagues and they will reverse out at some stage. Each club within that mini league gets either a positive or negative polarity and that will dictate their order of home and away games.

"There are clash dates, which is where in order to re-mix the home and away clubs, to make sure everyone plays each other, Glenn has to make them clash. Sometimes they'll both be away which is fine, sometimes they'll both be at home and we recognise this can be a problem so we make early contact with the clubs. Nine times out of 10 the police will move one to a Sunday or a Friday night, now and again they'll do them on the same day."

The process will be completed over the weekend when Thompson, Snellgrove and others involved put the finishing touches to the schedule. Soon, though, it will be time to start on next season.