Unlike many others this year perhaps, Myron Bell didn't have to think twice about which day he would celebrate Halloween. For once, he could have a two-for-one party because the holiday fell on his birthday--well, sort of.

Myron turned 12 yesterday, and for folks who listened to the Prince George's County police, yesterday was Halloween. Dressed as a girl, Myron and his 8-year-old sister, Ciara, a witch for the night, bypassed trick-or-treating and headed over to Six Flags America in Largo for a wicked night of fun.

"I just wanted to celebrate it on my birthday," said Myron, who lives in Glenarden with his grandmother, Dora McDonald. "I've never done that before."

Concerned because Oct. 31 fell on a school night, authorities in Prince George's and St. Mary's counties officially designated last night as Halloween and urged residents to send their ghosts, goblins and witches out then. The decision ignited controversy, particularly in St. Mary's, where commissioners were swamped with complaints from folks upset that anyone would dare tamper with tradition.

Nonetheless, many residents obliged.

But for others in the region, another night of fun awaits. This year, Halloween is not necessarily a one-night affair. Celebrants got to pick a night, and many of them--for religious or safety reasons--chose activities other than knocking on doors in their neighborhood to ask for a trick or treat.

Gail Jones, 32, of Upper Marlboro, plans to take her two children, ages 2 and 3, to a party at the Children's Museum in the District today.

"You can't trust nobody nowadays," she said yesterday, pushing a grocery cart outside the Wal-Mart in Bowie. She dug in her bag and pulled out the costumes that would transform her children into a cowgirl and a magician.

They would still get to have fun, she said, but safe fun.

"You don't know what they put in the candy," Jones said. "You have to get the candy X-rayed. I don't have time for all that."

Avis Massenburg, 33, of Capitol Heights, said two of her children celebrated at school Thursday, and the other three went to a Halloween party at her church Friday night. Yesterday, as other mothers scurried through Landover Mall in search of last-minute costumes and candy, she was calm.

"It's a chance for them to be taught about Christ and God," Massenburg said, explaining why she prefers the Christian "All Saints" celebration to the more traditional Halloween activity. "It's a good opportunity to witness to children and let them know they can celebrate but not like the world does."

As Mark and Derika Smith of Landover sat on a bench in a play area inside Landover Mall early yesterday, their 3-year-old daughter, Ajahnique, covered herself in colorful balls. This, of course, was just the prelude to her Halloween excitement.

Dressed as a Teletubby, little Ajahnique later would go door-to-door in her neighborhood, Summerfield, a rental military community in Landover. The Smiths said they had no doubt their neighbors would be prepared because, like the county police, military officials had urged parents to celebrate last night.

"We're military, and that's when the base is celebrating," Derika Smith, 25, said. "It's more convenient."

But Smith bought lots of candy, just in case somebody didn't get the word.

"If they come [Sunday], I'll still give them candy," she said.