DETROIT (Reuters) - What day is it? Don't ask the driver of General Motors Corp.'s Pontiac Grand Prix.

Due to a software glitch, the computer display in the 2004 model year Grand Prix shows the wrong day of the week, Pontiac spokesman Jim Hopson said on Monday. Engineers overlooked the fact that 2004 is a leap year, with an extra day,

"Somehow or other, the fact that this was a leap year got missed," Hopson said. "We are working on a solution."

GM may be able to fix the problem by resetting the software. A more costly solution could include replacing the display unit, he said.

The redesigned Grand Prix went on sale last March, and all models since then could potentially be affected by the glitch, Hopson said.

Despite studies showing improved quality and durability, GM has been hit by a high number of vehicle recalls this year. Last week, GM said it would recall more than 4 million full-size pickup trucks to replace tailgate support cables that may corrode and fracture.