A nationwide round of applause is set to take place on Sunday evening to mark the 72nd anniversary of the National Health Service.
On the eve of the event, Britons observed a minute's silence and lit a candle in memory of those who have died during the coronavirus pandemic.
Boris Johnson took part, with Downing Street lighting up in blue on Saturday night as a candle burned at the Prime Minister's official residence at 9pm.
Mr Johnson will meet NHS workers in the Number 10 garden on Sunday afternoon.
At a Downing Street press conference on Friday, he urged the public to clap for "those who have worked tirelessly and selflessly to help the nation get through this pandemic".
The Prince of Wales and Labour leader Sir Kier Starmer also paid tribute to the NHS.
Other public buildings including Royal Albert Hall, Blackpool Tower, the Shard and the Wembley Arch were lit up in blue in tribute to the NHS.
The NHS represents the very best of us and we will always be there to support it. https://t.co/9LlBSYaosr— Boris Johnson #StayAlert (@BorisJohnson) July 4, 2020
The nationwide clap follows the success of the weekly Clap for Carers during the coronavirus outbreak and it is hoped that the applause, which is planned for 5pm on Sunday, will become an annual tradition.
NHS chief executive Sir Simon Stevens said he hoped the public would use the anniversary as an opportunity to "say a heartfelt thank you" to hospital staff.
Sir Simon said: "This year has been the most challenging in NHS history, with staff displaying extraordinary dedication, skill and compassion to care for the 100,000 patients with Covid-19 who needed specialist hospital treatment and many others besides.
"During this testing time our nurses, doctors, physios, pharmacists and countless more colleagues were sustained by the support of the public, not least through the weekly applause for key workers.
"No health service, not even the NHS, could have coped alone with this coronavirus pandemic."
The Prince of Wales said: "The current pandemic means that the NHS - and the entire country - has been through the most testing time in the service's history.
"Our remarkably selfless nurses, doctors, paramedics and countless other staff have made costly sacrifices to provide treatment for more than a hundred-thousand patients with coronavirus and thousands more who needed other care.
"And, in tribute to them, we have come together as a nation to thank them for their skill, professionalism and dedication."
The nationwide clap has been organised following a letter from the Together coalition, in which influential figures including Sir Simon and the Archbishop of Canterbury Justin Welby voiced their support for making July 5 an official day of commemoration.
Labour leader Sir Keir Starmer said the health service had a personal resonance for him because his late mother was a nurse and later relied on the NHS as she became ill.
"Many, many times she got gravely ill and it was the NHS that she turned to, and I remember as a boy, a teenager, being in high-dependency units, in intensive-care units, with my mum, watching nurses and other support staff keep my mum alive," he said.
"They did that on more than one occasion - it's etched in my memory. For them, it was just the day job. They were doing that every day.
"So, it's very personal for me and I'm very grateful to the NHS and my mum was very grateful; she loved the NHS through the many decades that she absolutely depended on them."
Tomorrow, on the 72nd birthday of our NHS, I'm joining the rest of the country at 5pm to say thank you to all those who served on the frontline against Covid-19.— Keir Starmer (@Keir_Starmer) July 4, 2020
@togethercoalit #ThankyouTogether pic.twitter.com/sRThMwALqW
Sir Keir said NHS staff needed a pay boost in the wake of the coronavirus outbreak.
He made the call during a virtual rally marking the 72 years of the NHS in which he praised health service staff for their efforts during the pandemic.
"The pride and the thanks that we have for the NHS, which is always there, is reinforced this year by everything that all the staff in the NHS have done in relation to the Covid crisis," he said.
"Of course, we're not through that, and it will be our NHS heroes and the bravery of what they do which will get us through whatever comes next.
"That's why it's very important that we don't just say thanks, but recognise in a meaningful way what the NHS has done.
"And that's why Labour supports those calling on the Government today to make an immediate commitment to talks on a pay rise for NHS workers."
Landmarks across the country will light up blue tonight as we remember those we have sadly lost during the pandemic. Join us by shining a light in your window so we can remember together. 💙 #LightItBlue https://t.co/CjTchp3J1E pic.twitter.com/95jJlyeFKB— NHS England and NHS Improvement (@NHSEngland) July 4, 2020
The comments came after unions representing more than 1.3 million nurses, cleaners, physiotherapists, healthcare assistants, dieticians, radiographers, porters, midwives, paramedics and other NHS employees wrote to the Chancellor and the Prime Minister calling for pay talks to start soon.