Estimated declaration times have always come with a warning they could be taken only as a rough guide and were subject to change in the light of new information.
However, in the case of the May 2021 elections, they have been very difficult to produce because of the circumstances of the pandemic, as authorities are unsure how long it will take to count votes while keeping to social distancing requirements.
Although voting ends at 10pm on Thursday, the final results are not expected until Monday.
City Hall London elections
In London, the results of the mayor election, where Sadiq Khan is the bookies’ favourite to retain City Hall, and the London-wide PR top-up seat may come late on Saturday but could be on Sunday.
The results from seven constituency seats may be declared on Friday evening – Bexley & Bromley, Brent & Harrow, Ealing & Hillingdon, Havering & Redbridge, Lambeth & Southwark, North East and West Central.
The remaining seven seats, elected under the First Past The Post (FPTP) system, will be declared on Saturday afternoon and evening.
These include Barnet & Camden, City & East, Croydon & Sutton, Enfield & Haringey, Greenwich & Lewisham, Merton & Wandsworth, and South West.
In the Scottish Parliament election, there are 73 FPTP constituencies and eight regional proportional representation top-up seats, electing a total of 129 MSPs in a crucial contest which will give an indication of the level of support for the SNP’s push for a fresh vote on independence.
A majority of FPTP seats, 46 in all, are expected to count during the day on Friday with results due from about lunchtime, peaking in the evening.
The remaining 27 FPTP constituencies are understood to be planning to count in the day on Saturday with results due from about lunchtime.
Results from the eight regional PR top-up seats are expected on Saturday night, with Scotland Mid & Fife possibly around 6pm, and Scotland West at 7pm.
In Wales, voting is in 40 FPTP constituencies and five regional PR top-up seats, and counting is due to take place in the day on Friday, with results from FPTP seats expected from about 3pm and peaking about 5pm.
Results from the five regional PR top-up seats are expected later on Friday night.
There are 12 other mayoral contests taking place in England, with Doncaster counting overnight with the result expected early on Friday morning.
Liverpool is counting during the day on Friday, with the result expected possibly at 2.30pm, while seven counts are are understood to be planned for Saturday, with results due from about noon – Bristol; Greater Manchester; Liverpool City Region (possibly 12.30pm); North Tyneside (noon); Salford; West of England; West Midlands.
The Bristol mayoral result is expected in the evening, perhaps around 6pm, following the result of the West of England regional mayoral poll, which could be at noon
The West Yorkshire count is expected during the day on Sunday, and timings have not been confirmed for Cambridgeshire & Peterborough, and for Tees Valley.
A by-election will also take place in Hartlepool to select a new MP, with the result likely to be announced between 4am and 6am.
Police and Crime Commissioners
Finally, there are elections for 39 Police and Crime Commissioners (PCC) in England and Wales, with counts for four expected during the day on Friday, with results in the afternoon and evening: Avon & Somerset; Bedfordshire (5pm); Cleveland (2pm); and Staffordshire.
Three of the four Welsh PCC counts are expected to be during the day on Sunday: Dyfed-Powys; Gwent; and North Wales. The South Wales count may also take place then.
Fifteen counts are due during the day on Monday, with results in the afternoon and evening: Devon & Cornwall; Gloucestershire; Hampshire; Hertfordshire; Kent; Lancashire; Cumbria; Northamptonshire; South Yorkshire; Suffolk; Sussex; Thames Valley; Warwickshire; Wiltshire; and West Mercia.
Additional reporting by the Press Association.