A US consulting film has calculated the film's release has cost $627m (£342m) in lost productivity.
Consulting firm Challenger, Gray and Christmas said the buzz about the film would prompt many people to skip work for daytime screenings.
"Already, we were looking at huge opening weekend audiences who have long anticipated the grand finale in this 28-year journey," said John Challenger.
He predicted the loss to companies based on absenteeism caused by the other prequels, the proportion in full-time work, and their average pay.
Fans in Leicester Square
Fans may skip work for daytime screenings, a consultant says
"Of course, these estimates are probably on the conservative side in light of the great reviews the movie is receiving," he said.
Several overseas markets have already reported advance takings higher than the box office grosses of the previous prequels, The Phantom Menace and Attack of the Clones.
The massive interest in the film, which was premiered in Cannes on the weekend, has prompted many midnight screenings.
"We are seeing phenomenal advance ticket sales in many territories," Paul Hanneman, Fox International's exec VP for sales and strategic planning, told US magazine Variety.
One theatre chain said its advance sales were 60% higher than for The Lord of the Rings - The Return of the King, which took US$124m (£67.66m) in its first five days in North America.
"It is gigantic," said Fandango executive Art Levitt. "For those who are waiting for the opening bell to ring on summer, it's rung loud and clear."