Here is the day's schedule (from bbc.co.uk/tv)
Prince Charles and Camilla Parker Bowles will marry at 1230 BST on Saturday, at Windsor Guildhall.
The ceremony will be followed by a dedication service inside the castle.
Below is a timetable for the royal wedding day.
Morning: Prince Charles arrives at Windsor Castle from Highgrove, while Camilla arrives at the Castle after leaving Clarence House.
1225 BST: Charles and Camilla depart Windsor Castle together by car, via King George IV and Cambridge Gates for the Guildhall.
1230 BST: The couple arrive at the Guildhall for the civil ceremony.
1255 BST: Charles and Camilla - now known as HRH the Duchess of Cornwall - leave the Guildhall and return to Windsor Castle.
1430 BST: The couple arrive for the Service of Prayer and Dedication at Galilee Porch, St George's Chapel, and are met by the Dean of Windsor and the Archbishop of Canterbury.
After Charles and Camilla are taken to the quire, the congregation sing the Processional Hymn.
The couple stand before the high altar and prayers are said before former Archbishop of Canterbury Lord Carey reads from the Book of Revelation.
The choir of St George's Chapel sings a setting of a creed from the Russian Orthodox Liturgy by Aleksandr Gretchaninov.
After a further prayer, Charles and Camilla stand before the archbishop and make their pledges. Afterwards, the congregation sings the hymn, Love Divine All Love Excelling.
Actor Timothy West then reads William Wordsworth's Ode on Intimations of Immortality before the choir and members of the Philharmonia Orchestra perform Bach's Nun Komm der Heiden Heiland.
The Dean of Windsor leads prayers from the lectern in the nave and the congregation sings the hymn Praise My Soul, the King of Heaven.
The archbishop brings proceedings to a close before the National Anthem is played. It is followed by the Voluntary Celebration Fanfare, by Alun Hoddinott.
1515 BST: The Service of Prayer and Dedication ends.
1517 BST: Charles and Camilla depart St George's Chapel by the West Door and are joined by the Queen, other members of the Royal Family, the Shand family, the Archbishop of Canterbury, and the Dean of Windsor.
1520 BST: The couple meet representatives from a number of their charities and organisations in the Horseshoe Cloister.
1545 BST: The Prince of Wales and the Duchess of Cornwall drive from Henry VIII Gate to the State Apartments for the reception given by the Queen.
Around 1745 BST: The Prince of Wales and the Duchess of Cornwall leave Windsor Castle for their honeymoon in Scotland.
Around 1945 BST: The couple arrive in Aberdeen where they are met by pipers and airport staff.