Prince Harry and Meghan Markle's ceremony will begin at noon local time, which is 7 a.m. ET | 4 a.m. PT.
The wedding will be conducted by The Right Rev. David Conner, the dean of Windsor. As the couple makes their vows, The Most Rev. Justin Welby, the Archbishop of Canterbury will officiate. Welby also conducted Prince George's christening, according to ABC News.
The wedding service will begin at 12noon at St George's Chapel. The Dean of Windsor will conduct the service and The Archbishop of Canterbury will officiate as the couple make their vows. pic.twitter.com/dTS56fy22c— Kensington Palace (@KensingtonRoyal) February 12, 2018
It was previously announced that the wedding will take place at Windsor Castle, the oldest and largest occupied castle in the world. Another royal wedding, that of Princess Eugenie, will take place there later in the year.
Approximately 600 guests have been invited to the ceremony at St. George's Chapel on the castle grounds, though an exact list has yet to be released. The venue, which can seat approximately 800 people, is where Harry was baptized in 1984.
At the wedding, the royal couple also plans to honor the memory of the late Princess Diana, Harry's mother, who died in a Paris car crash in 1997.
Forecasters are predicting highs of around 18 degrees Celsius (64 F) for the royal wedding. It is also supposed to be sunny for much of the day in Windsor.
THE WEDDING PARTY
Markle will not have a maid of honor, but Harry has chosen his brother William as his best man. Harry was best man when William married Kate Middleton at Westminster Abbey in 2011.
All the bridesmaids and page boys will be children, according to Harry's press secretary, Jason Knauf. That may mean a role for Prince George, 4, and Princess Charlotte, 3, the children of Prince William and the Duchess of Cambridge. But don't bother looking for Prince Louis - born in late April - as the youngest prince will not attend the wedding.
Markle's mother will meet with Queen Elizabeth II and other royals before the wedding and will have a special role in the ceremony, according to a palace spokesman. Her father will not be present. In his absence, Prince Charles will walk Markle down the aisle.
Kensington Palace hasn't yet announced the designer of Markle's wedding dress, but Ralph & Russo (the same duo behind the black dress in her engagement photo), Erdem Moralioglu, Christopher Bailey and Roland Mouret have reportedly emerged as frontrunners. No matter who Markle picks to design her dress, she'll have to get the queen's final approval.
The palace on Saturday revealed details about the rings, both made by Cleave and Company. Markle's ring was a gift from the queen, and it was fashioned from a piece of Welsh gold. Prince Harry's ring has a platinum band with a textured finish, according to the palace.
The couple will take a carriage ride through the town immediately after the ceremony, letting everybody in on the Royal Wedding fun.
They've invited 2,640 people from all walks of life to the grounds of Windsor Castle for a prime view of the procession. About 1,200 of those invited will be members of the general public. Around 200 will represent charities and other organizations supported by the couple, with local schoolchildren, residents of Windsor and members of the Royal Household making up the balance.
At 1pm the couple, now married, will undertake a Carriage Procession from St George's Chapel through Windsor Town returning to Windsor Castle along the Long Walk. pic.twitter.com/Lw6RaqY0p5— Kensington Palace (@KensingtonRoyal) February 12, 2018
"They hope this short journey will provide an opportunity for more people to come together around Windsor and to enjoy the atmosphere of this special day," the royal family wrote on Twitter of the procession.
The couple has chosen an open-topped Ascot Landau from the royal carriage collection to use in their procession. If it rains, the couple will use the Scottish State Coach, which has a glass roof.
THE FOOD, DRINK AND CELEBRATION
Following the ride, the couple will return to the castle for a reception with 600 invited guests in St George's Hall. Prince Harry's father, Prince Charles, will then hold a private reception for 200 invited guests at Frogmore House, which is close to Windsor Castle.
As for the bubbly, the queen is reportedly fond of Nyetimber, a high-quality English sparkling wine. The cake will be prepared by pastry chef Claire Ptak. It will be a lemon elderflower cake covered with buttercream and decorated with fresh flowers.
Philippa Craddock is the event's floral designer. She will direct a team including florists from St. George's Chapel and Buckingham Palace. Craddock plans to use locally sourced foliage from the surrounding parkland for many of the displays. The flowers will be given to charities after the wedding.
It's not yet clear where the newest royal couple will spend their honeymoon, but they won't be leaving right after the wedding. They plan to make their first public appearance as a married couple during the week following the ceremony. In the past, they have traveled in Africa together.
The Associated Press contributed to this report.