The last Friday before Christmas is the traditional office party night, but licensees, hotels and taxi bosses are predicting it will be spread over two Fridays this year, with a massive influx of partygoers expected tomorrow night as well as the following Friday.
Glasgow is already attracting record numbers of revellers to the city centre. Figures from last weekend show the city's marshalled taxi ranks were the busiest they have been in almost five years.
More than 11,344 revellers queued for taxis across the city centre's four NiteZones last Friday and Saturday night, compared with 9137 last year.
Restaurants and hotels are also reporting record bookings this month.
Glasgow Taxis Ltd expects 35,000 hires on the last two Fridays before Christmas.
The firm will have its full fleet of almost 1000 taxis on the roads to cope with demand.
Eleanor Lee, of Glasgow Community Safety Services, said: "Glasgow really is the place to be this Christmas.
"Last Friday was the busiest we have seen in almost five years. We were really surprised by the figures.
"There were 11,344 people across the four NiteZones. There were 4935 in Gordon Street alone and 3479 on the Sauchiehall Street zone.
"We are expecting tomorrow night to be even busier.
"Although December 21 is the last Friday before Christmas and traditionally the busiest night, the reports we are getting about bookings is that tomorrow night is going to be just as busy.
"It's not just the pubs and clubs saying they are busy but hotels and restaurants are all heavily booked."
However, with the massive influx into the city centre, police are urging revellers to stay safe, warning that violent crime and sexual assaults tend to spike over the festive period.
Strathclyde Police said it had put extra resources in place in all parts of the city to cope with the influx of office parties.
Volunteer 'Street Pastors' will also be patrolling the city and a special SOS bus will be parked on Gordon Street to offer advice to vulnerable revellers.
British Transport Police will have dozens of extra officers manning the city's main railway stations, including Queen Street and Central as part of Operation Thistle.
Officers will be targeting passengers who flout a ban on alcohol on ScotRail trains as well as helping keep passengers safe on rail platforms and quieter stations.
A spokesman for BTP said: "We would remind passengers they may be refused entry to trains if they are drunk and disorderly."
However, safety chiefs say they are encouraged by the high numbers using the city's marshalled NiteZones.
The city has five NiteZones in operation over the festive period at Gordon Street, Sauchiehall Street, Albion Street, Byres Road and Shawlands.
Posters have been displayed in clubs and pubs with the message, "All I want for Christmas is to keep you Safe" as part of a campaign by Strathclyde Police.
Revellers with smartphones will have access to an app which links to train and bus timetables.
Partygoers, particularly women, are being reminded to use only licensed taxi firms and to avoid walking in unlit areas including city centre lanes.
Chief Superintendent George Nedley, of Strathclyde Police, said: "We are anticipating a double Black Friday this year because of the way it's fallen.
"It is generally the last Friday before Christmas but we have plans in place around the city for people going out for their Christmas nights out.
"The message is be sensible, plan your night and don't get yourself involved into a situation you can't get out of.
"We are working very closely with the licensing trade, First Bus and ScotRail.
"There tends to be a spike in violent crime and sexual assaults at this time.
"However, individuals have an important role to play in this by making sure they don't drink to excess."
Stephen Flynn, vice chairman of Glasgow Taxis Ltd, said: "We'll have our full fleet, of almost 1000 taxis on the roads, as well as extra staff on each of the NiteZones, to ensure people can get in and out of the city centre quickly and safely.
"We're expecting to take more than 35,000 hires each evening through street pick-ups, our Nite Zones, over the phone or via our app, so it will be all hands on deck for these two extremely busy nights.
"We also advise members of the public to be extra careful when they are exiting vehicles to ensure they have not left behind any possessions as our drivers often find an interesting selection of lost property around this time of year, which they'll always endeavour to return to the rightful owner."