TOLEDO, Ohio (AP) _ Dave Bourland's science class may question everything he has to say for the rest of the school year, but that was the purpose of a weeklong scientific spoof.

Bourland told his ninth-grade general science students at Libbey High School last week that they would have to send their watches and calendars to the state capital for conversion when the United States switched to a ''metric time system.''

The system would mean that clock faces would be changed to all 10s, hours would have 100 minutes and there would be only 10 hours of daylight and 10 months in the year, Bourland told the class. Students who were born in July or August would have their birthdays canceled, he said.

Bourland devised the scenario to instill a spirit of scientific skepticism in his students. But he was dismayed that no one questioned his statements, even when he told them that the change would mean their summer vacations would be reduced to 20 days.

''No one actually sat down with a pencil and tried to figure it out,'' Bourland said Friday. ''No one came up with the fact that it would not have worked.

''They don't think. That's the biggest thing educators are fighting against,'' he said. ''They said that some questions had crossed their mind, but they didn't ask the questions. And I wouldn't have had an answer.''

Bourland finally told the students Wednesday that he'd been fibbing.

''They liked it. They definitely learned a great deal from this,'' he said. ''In fact, I told them I was calling (The Associated Press) and they said, 'Prove it.' ''

The idea of measuring time in decimal increments is not completely ridiculous because any form of measurement is possible, said school principal Bill Shafer.

''Except when you know that time is based on the revolution of the earth, then you realize that metric time might not be an appropriate approach,'' Shafer said.

The students were not the only ones fooled: Some parents called the school to ask when metric time would begin.

Bourland has spoofed students before. He told another class that people did not have the ability to see colors until color television was invented.