The polls have already opened.
We may not know how things stand until the morning, and even then it may take weeks to form a government. (And if you haven’t already signed up for our post-election survival guide, do it now before the polls shut!)
However, if you’re planning on staying up for part (or even all of the night), here’s what to watch out for.
10pm: The polls close
The polls close at 10pm sharp.
A few minutes afterwards, the exit poll will be released. These exit polls are generally accurate, correctly calling the last four elections.
However, the rise of traditionally smaller parties, the unique situation in Scotland and several hard-fought individual contests, make the pollster’s task much harder.
There is also the possibility that people may simply lie, skewing the result. In 1992, the exit polls infamously predicted a hung parliament (albeit with the Conservatives as the largest party). In the end, John Major was returned to office with a majority of seats and a wide margin in votes.
11pm: First English results
Houghton and Sunderland South is expected to be the first to declare, followed by a handful of other northern constituencies over the next 90 minutes.
While these are all safe Labour seats, it may give an indication of the swing between Labour and the Conservatives.
1am: First marginal constituency
Nuneaton is a marginal constituency and 38th on Labour’s target list. If they aren’t able to overturn the Conservative majority of 2,069, then they might be in trouble.
While Labour is very unlikely to lose Dagenham and Rainham, the swing there might give an indication to how the contests in London may pan out.
Na h-Eileanan an Iar (the Western Isles) is expected to be the first Scottish seat to declare. While the SNP should increase their majority, again the size of the swing may give hints about the scale of the ‘ajockalypse’.
2am: More seats start to declare
The trickle of results starts to become a flood, with 72 results expected in the space of half and hour.
These include several Scottish seats, including Kirkcaldy (the safest Labour seat). If the SNP is able to win there, we can expect party leader Nicola Sturgeon to be very happy.
In London, the key marginal is Battersea, where a victory would be very good for Ed Miliband, the Labour leader.
3am – 4.30am: Will we see this election’s Portillo moments?
Just as even the most ardent vote watchers might be starting to flag, over a period of 90 minutes, we’ll see results from nearly 400 seats, including some key battlegrounds, come in.
In Scotland, all the Glasgow seats will declare at 3am, followed by the Edinburgh constituencies an hour later.
In London, Bermondsey and Old Southwark (where I’ll be) at 3am, and Sheffield Hallam at 4.30am could provide ‘Portillo moments’ for both Lib Dems Simon Hughes and Nick Clegg respectively.
If the Conservatives are doing especially badly, prime minister David Cameron may use his count at Witney to concede the overall contest (though obviously, he will retain his seat). Of course, Ed Miliband could do the same at Doncaster North at 4am.
Thurrock, a three-way Labour/Conservative/Ukip contest, will declare at 3am.
5am – 6.30am: Make or break for Nigel Farage
While the bulk of the counts will be announced by 5am, 160 seats are still expected to declare between 5am and 6.30am.
As well as many safer Conservative seats, this includes several Lib Dem-Conservative contests, such as Mid Dorset and North Poole (5am) and St Austell and Newquay (6.30am).
Thanet South, the three-way contest involving Ukip’s Nigel Farage will declare at 6am.
7am onward: Still all to play for?
Only 23 seats are expected to declare after 6.30am. However, if it comes down to the wire then we may have to wait for St Ives, currently held by the Liberal Democrats, (expected at 1pm) for a complete picture.