A minute's silence and a national doorstep vigil will form part of a day of reflection to mark the anniversary of the UK's first Covid lockdown.
Prime Minister Boris Johnson is backing charity Marie Curie's plan for Tuesday 23 March, when those who have died in the pandemic will be remembered.
There will be a minute's silence at 12:00 GMT with people encouraged to light up their doorsteps that night.
Prominent buildings and landmarks will also be illuminated across the UK.
Mr Johnson announced the first national stay-at-home order on 23 March 2020, days after warning many families would "lose loved ones before their time".
Since then there have been three periods of national restrictions, as well as the introduction of levels and tiers of measures in all four nations.
The past 12 months have also seen coronavirus vaccines developed from scratch, with 23.3m people in the UK having now received a first dose.
'Incredibly difficult year'
The prime minister said he would observe the minute's silence at noon privately.
Other senior politicians have given their support to the event, with Labour leader Sir Keir Starmer, Scottish First Minister Nicola Sturgeon and Welsh First Minister Mark Drakeford all saying they would take part.
Mr Johnson said: "This has been an incredibly difficult year for our country. My thoughts are with all those who have lost loved ones, and who have not been able to pay tribute to them in the way they would have wanted.
"As we continue to make progress against the virus, I want to thank people for the sacrifices they continue to make, and hope they can look forward to being reunited with loved ones as restrictions are cautiously eased."
Alongside the minute's silence and doorstep vigil, the day will also see community-led activities take place, such as virtual assemblies, choirs, services and yellow ribbons being wrapped around trees.
A series of free online talks organised by the Good Grief Festival will also take place, featuring experts, bereaved families and celebrities.
It is hoped people will help create a nationwide "beacon of remembrance" on their doorsteps by beaming phones, candles and torches into the night sky at 20:00.
Marie Curie chief executive Matthew Reed said it was "important that we all come together to reflect on our collective loss, celebrate the lives of the special people no longer here, support those who've been bereaved and look towards a much brighter future".
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