Wales’ 17-day “firebreak” lockdown will start later, with the health minister saying the aim is to bring “a much more normal Christmas season”.
Vaughan Gething said delaying lockdown measures would have impacted December trade for businesses.
People are being told to stay at home and pubs, restaurants, hotels and non-essential shops will shut, for the lockdown from 18:00 BST.
Is is aimed to “slow” the rise of Covid cases and hospital admissions.
Economists have warned the lockdown may cost the Welsh economy more than £500m.
Gatherings indoors and outdoors with people not in your household are banned from Friday evening until 9 November.
The national lockdown brings an end to the local lockdowns imposed on 15 counties, as well as the city of Bangor and town of Llanelli in recent weeks.
People can be fined £60 for a first coronavirus restrictions offence, up to a maximum fixed penalty notice of £1,920. But if prosecuted, courts can impose an unlimited fine.
Primary schools will reopen after next week’s half-term break, but only Years 7 and 8 in secondary schools can return at that time under the new rules.
‘Christmas season important’
Speaking on BBC Radio Wales Breakfast, Mr Gething said there would be “greater” economic harm if the Welsh NHS becomes overwhelmed and there were “deeper and harder” measures for a longer period of time.
“If we do this now and if we then have a consistent set of national rules, to keep the transmission and the intensity of the virus at a lower level, then we can have a much more normal Christmas season for businesses,” he said.
“The month of December is really important for many businesses, if we delayed, we would have almost certainly impacted upon that part of the season.”
Dr Margaret Harris, World Health Organisation spokeswoman, said people should start planning how to safely celebrate Christmas.
“It will be a new Christmas, but we can enjoy our time together,” she said. “We just have to do it slightly apart.”
Why is Wales going into lockdown?
The UK’s average is between 1.3 and 1.5.
Even though Wales has some of the lowest coronavirus infection rates in the UK, First Minister Mark Drakeford said that without this lockdown the Welsh NHS would not be able to cope.
The number of patients in hospital with Covid-19 in Wales “is the highest it has been since June”, Health Minister Vaughan Gething said on Wednesday.
He said 894 people were in Welsh hospitals with the virus, up 26% week-on-week, while 43 of them are in critical care, a rise of 72%.
That is still below the 1,400 Covid-19 patients – with 164 of them in intensive care – in Welsh hospitals with coronavirus during the height of pandemic.
Yet despite the lower number of cases, ministers said they needed to act now so the NHS can keep essential hospital services and treatments running on top of expected winter pressures and not get overwhelmed.
What shops will stay open in Wales?
Food shops, off-licences and pharmacies can stay open but supermarkets will be unable to sell items like clothes during Wales’ temporary lockdown.
Mr Drakeford said it would be “made clear” to them they are only able to open parts of their business that sell “essential goods”.
Business leaders say companies in Wales have been given just hours to finalise plans for the firebreak.
Among those affected was the former winner of the BBC’s The Apprentice, Alana Spencer, who was due to open a new cafe on the Aberystwyth sea front on Friday.
In a tearful social media post, she said he was “gutted” by the timing and later added it was a “devastating blow” to her new bakery and cafe business.
“I took to social media and I had a small melt-down,” she said.
However she told BBC Radio Wales she will now use the takeaway service during lockdown to trial new products.
“Luckily we have a hatch on the front so we can do takeaway, so we’ll take it from there and open properly at the end of the lockdown,” she said.
“It’s a bitter pill to swallow, when we are in Ceredigion, we have lower numbers and we are being very sensible here, but ultimately people’s lives are at risk.”
How much can you be fined?
People can be issued a fixed penalty notice “for most types of breaches” of the coronavirus regulations and fined £60 for the first offence.
That fine is increased to £120 for a second offence and continues to double for repeated offences, up to a maximum of £1,920. If prosecuted, however, a court can impose an unlimited fine.
Organisers of unlicensed music events of more than 30 people could face a conviction with an unlimited fine or a fixed penalty of £10,000.
What do people think?
Residents of Caerphilly county were the first to go into a local lockdown on 8 September and “they’re trying to get on with their lives”.
Key worker Lois Griffiths’s son and daughter will continue to go to a childminder as she has to carry on working.
“I’ve got to carry on with my life,” she said. “We can’t just stick in the house and do nothing – we’ve got to earn money.”
Her 10-year-old daughter Amy is disappointed because lockdown means she can’t go to her dance class.
“I feel really sad because I’ve got ‘Team’ coming up and I don’t want to stop doing that,” she said.
Unique Creations has been “chock-a-block” as people want a pre-lockdown trim before the hair salon on Blackwood High Street closes on Friday evening.
“We’re flat out,” said stylist Ellen Watkins.
“I’m hoping it will be the same when we come back but I don’t really know. There’s a lot of worry. I’m looking to buy a house.
“Financially where am I going to be if the salon can’t open back up? It’s a really scary time for me.”
How does lockdown impact business?
The timing of Wales’ “firebreak” lockdown has been called “an absolute dog’s dinner” for Welsh businesses as it straddles two UK government financial support schemes – and firms will have to apply for both separately.
Mr Drakeford said he feared employees could face redundancy if the Treasury does not change its support for workers.
Chancellor Rishi Sunak declined a request for the new scheme to be brought forward in Wales as the Welsh Labour Government said it offered to pay the cost for the difference between furlough and the JSS, estimated at £11m.
But the Conservative UK government said ministers in Cardiff knew “full well” it was not possible for the Treasury, adding the timing of Wales’ lockdown was “very, very unfair” on people “caught by the time gap”.
Economic researchers say the lockdown could cost between half and three-quarters of a billion pounds.
The National Institute Of Economic and Social Research says that “up-front cost must be set against potential economic benefits after lockdown if it is successful in reducing the spread of the virus and restoring economic confidence.
More than 100,000 people in Wales work in the accommodation and food industries while nearly 200,000 work in the wholesale and retail trades and car repairs.
Estate agents have to close and house viewings and valuations have to stop, a blow for the Haus agency which is to open its new Cardiff branch on Friday – only to close for two weeks in the evening.
“It’s been such a challenging time,” said director Chris Birch.
“Everything involved in running a business, let alone moving in a global pandemic, has taken so much longer and the admin and red tape is another level.”
Will a Wales-wide lockdown work?
Public health officials and politicians have warned they will not know the full impact of the firebreak lockdown until after it ends on 9 November.
Giri Shankar, from Public Health Wales, said there was “always a lag phase of about two to three weeks” before any visible change of that intervention can be measured and detected”.
But the first minister has said the lockdown end date is fixed as to avoid further harm to the economy.
Wales, though, has been warned of the possibility of another lockdown early in the new year if Covid-19 starts spreading quickly again at Christmas.
Economy Minister Ken Skates said ministers “could not rule out the possibility of introducing another firebreak if over the Christmas period transmission rates increase dramatically.”
Find out how the pandemic has affected your area and how it compares with the national average: