The late President George H.W. Bush’s funeral service and related ceremonies will cost American taxpayers at least a half-billion dollars in lost productivity and wages for federal workers and other expenses.

Bush, who died on Nov. 30 at age 94, will be laid to rest on Thursday at his presidential library in College Station, Texas.

Following tradition for presidential funerals, the federal government shut down on Wednesday and the 41st president’s casket was transported across the country on Air Force One for a public viewing in Washington, D.C.

The paid holiday for federal workers — including Congress and the U.S. Postal Service — could cost taxpayers upwards of $450 million, according to estimates.

A 2008 analysis by the National Taxpayers Union found that federal holidays cost taxpayers around $450 million per day in holiday pay and lost labor. That figure is based on 2004 U.S. economic data. The figure is not adjusted for inflation, and federal salaries and the federal workforce have grown since then, making it almost certain the estimate is low.

Presidential funerals — which take years of government planning — are traditionally expensive affairs.

Taxpayers paid $423 million for federal workers to take the day off for former President Ronald Reagan’s funeral in 2004, according to a UPI report. Adjusting for inflation, that figure would be $566 million today.

For Bush, President Trump authorized the modified Boeing 747 that serves as Air Force One to fly from Washington to Houston this week to pick up Bush’s casket and bring it to the Capitol for a public viewing in the Rotunda.

The presidential plane, which also carried former President George W. Bush and other Bush relatives, made a return flight to Houston on Wednesday. Flight costs for the two round-trip flights between Houston and Washington, D.C. — which run at more than $200,000 per hour — could add up to at least $2 million in travel expenses.

Use of the presidential plane is in line with previous presidential funerals. In 2004, George W. Bush authorized the plane to transport Reagan’s casket.

Other ceremonial flourishes for George H.W. Bush, such as a 21-plane military flyover honoring the late president’s service in the Navy during World War II, could tack on another $126,000.

These estimates don’t include other likely costs that will be difficult to assess until after the funeral — such as increased security and Secret Service protection for the high-profile political attendees in Washington, D.C., and Texas.

It also doesn’t include nebulous costs, such as opportunity losses at the New York Stock Exchange and Nasdaq, which both closed shop on Wednesday to honor the late president. The shutdown of the U.S. Postal Service during the busy holiday season could also impact American businesses that rely on its services.