The new dates follow French President Emmanuel Macron's extension of a ban on large public gatherings until mid-July.
While the news comes as a relief to professional cycling teams and fans, it also moves the three-week race out of its traditional slot in the summer holidays where roadside crowds of around 12 million would be expected to gather in festive spirit.
"Following the president's address on Monday evening, where large-scale events were banned in France until mid-July as a part of the fight against the spread of COVID-19, the organisers of the Tour de France, in agreement with the Union Cycliste Internationale (UCI), have decided to postpone the Tour de France to Saturday 29th August to Sunday 20th September 2020," a statement from the organisers said.
It said the race would follow the same route as the original itinertary, starting in Nice and ending in Paris.
The new date solves a series of problems after organisers faced up to the reality that the race could never take place on the original dates.
Top cycling teams will survive economically, social distancing will be easier without massive crowds, and the 4,500 strong Tour de France rolling caravan can be more easily put up in hotels outside August.
With the Tokyo Games and football's Euro 2020 both delayed by a year, the Tour is the last major event remaining on the summer sports calendar.
Elite cycling will breathe a huge sigh of relief as the Tour accounts for most of its earnings.
"The Tour represents around 60 percent of earnings in a season," French team AG2R boss Vincent Lavenu said last week.
The Tour will provide a daily fix for deprived sports addicts the world over, with millions of armchair fans able to tune in daily, including those still working from home.
Organisers Amaury Sports Organisation (ASO) had stubbornly refused to cancel the event, and while the new date is later than expected, it now gives them time to stage the warm-up Criterium du Dauphine -- held annually ahead of the Tour but postponed this year as the spring cycling season was swept aside by the coronavirus.
Cycling's governing body the UCI announced the new dates, saying that May's postponed Giro d'Italia would be raced after the Tour de France, and the Vuelta a espana after that, with daes to be annouced in May.
- Health comes first -
That eight-day jaunt through the Alps will likely attract huge attention, as all the top cyclists in the world will want to compete.
With May's Giro d'Italia being cancelled and also the prestigious Tokyo Olympic road race in late July on Mount Fuji, the Tour de France will be more competitive than ever as the whole spectrum of elite cyclists focus on the one race.
"The Tour de France is 3,000km of smiles," race director Christian Prudhomme has repeated many times in the past in reference to the Tour and its fans.
But he has also stressed that health comes first, ahead of the Tour de France, as the country battles the coronavirus crisis.
France has been under lockdown since March 17 in an attempt to slow the spread of the virus which has claimed the lives of over 15,700 people in the country.
The Tour de France then will likely become more of a shared national experience than usual and could be viewed by the general public as something of a return to normal with some predicting it could be part of the healing process from the lockdown.
"This period of confinement will hurt us all morally. We will need a cure for it and a Tour de France would help give us a sense of stability," 94-year-old former cyclist Raphael Geminiani told L'Equipe recently.
The epic race will now embark from Nice on the Mediterranean coast on August 29 and culminate over three weeks later on Paris's celebrated Champs Elysees on September 20, where the traditional yellow jersey is awarded to the winner beneath the Arc de Triomphe.