That's when Kate Middleton and Prince William, surrounded by their immediate families, are officially scheduled on the balcony of Buckingham Palace and expected to kiss – just as the groom's parents, Prince Charles and Princess Diana, did 30 years ago.
They will then watch the spectacle of a Royal Air Force flyover, the palace confirmed Friday.
As for the official, to-the-minute "ceremonial timings" on the big day (all London time):
Between 8:15 a.m. and 9:45 a.m.
The general congregation will arrive at the Great North Door of Westminster Abbey.
From 9:50 a.m.
Governors-General and Prime Ministers of Realm Countries, the Diplomatic Corps and other distinguished guests arrive at the Abbey.
10:10 a.m.
The Bridegroom and Prince Henry of Wales leave Clarence House. They arrive Westminster Abbey at 10:15 a.m.
10:20 a.m.
Members of Foreign Royal Families arrive at Westminster Abbey from Buckingham Palace.
Mrs. Michael (Carole) Middleton and Mr. James Middleton leave the Goring Hotel. They arrive Westminster Abbey at 10:27 a.m.
10:25 a.m.
Members of the Royal Family (except those listed below) leave Buckingham Palace. They arrive Westminster Abbey at 10:30 a.m.
10:35 a.m.
The following Members of the Royal Family leave Buckingham Palace. They arrive Westminster Abbey at 10:40 a.m.:
The Duke of York
Princess Beatrice of York
Princess Eugenie or York
The Earl and Countess of Wessex
The Princess Royal and Vice Admiral Timothy Laurence
10:38 a.m.
The Prince of Wales and The Duchess of Cornwall leave Clarence House. They arrive Westminster Abbey at 10:42 a.m.
10:40 a.m.
The Queen and The Duke of Edinburgh leave Buckingham Palace. They arrive Westminster Abbey at 10:45 a.m.
10:48 a.m.The Bridesmaids and Pages leave the Goring Hotel. They arrive Westminster Abbey at 10:55 a.m.
10:51 a.m.
The Bride, accompanied by Mr. Michael Middleton, leaves the Goring Hotel for Westminster Abbey.
11:00 a.m.
The Marriage Service begins (and will be relayed by audio speakers along the route).
12:15 p.m.
The Carriage Procession of the Bride and Bridegroom with a Captain's Escort of the Household Cavalry, followed by The Queen's Procession with a Sovereign's Escort of the Household Cavalry, leaves Westminster Abbey for Buckingham Palace.
12:30 p.m.
The Bride's Carriage Procession arrives at Buckingham Palace.
12:40 p.m.
Members of the Royal Family and Members of Foreign Royal Families arrive at Buckingham Palace.
From 12:40 p.m.
Other guests for the Reception arrive at Buckingham Palace.
1:25 p.m.
The Queen and the Bride and Bridegroom, together with their Families, appear on the Balcony.
1:30 p.m.
Fly Past by the Royal Air Force and Battle of Britain Memorial Flight.
Then the Queen's reception begins!
Princess Diana and Prince Charles kiss on their wedding day
Reginald Davis / REX Features
