The calendar is being oh so kind to demons and ghouls. Not only does Halloween fall on a Saturday night, but it's a turn-your- clocks-back-sleep-in-as-late-as-you-want-the-next-day Saturday night.

Halloween Saturday is the hour when the candyman comes and the climax of a scary season that began more than a month ago when the haunted houses started creaking open and your demented neighbor turned his lawn into a plastic cemetery.

Saturday should be nothing but devilish fun -- in the clubs, the haunts and on the sidewalks.

The city has set trick-or-treat time for 5:30 to 7:30 p.m., which means it's still going to be light outside when little Frankenstein is coming to your door. Can we all agree on a 15-minute grace period, at the very least, so kids can maintain their sugar high through Christmas?

In the meantime, here's an all-ages Halloween rundown:

Would you be even remotely surprised to learn that Steve O'Hearn -- brilliant musician, designer and co-founder of Squonk Opera -- won the costume contest in third grade?

Of course not!

"Dodo Bird," he says. "You know, chicken wire and fabric and feathers."

This weekend the performance troupe sets up its Squonk Shop at the Kelly-Strayhorn Theater in East Liberty, where kids can get help making their own masks and costumes.

Saturday's Halloween Mayhem Day, a free, family-friendly event, will feature trick-or-treating and arts activities from 1 to 5 p.m. glass-making demos by Pittsburgh Glass Center and performances by Hope Academy of Music and Arts, Propel Homestead, Alumni Theater Company and Temujin the Storyteller.

As darkness creeps in, Squonk will unveil its 16-foot Demon of Mayhem head on the roof, and Mayhem Night will commence with screenings of the horror classics "White Zombie," "Plan 9 From Outer Space" and "Night of the Living Dead," and sets by global beats band Soma Mestizo, puppeteer Dave English and the Schmutz Company. It runs from 8 p.m. to 2 a.m. for ages 16 and older ($10 at the door or $5 with costume).

Why all this Squonk Mayhem? The company is beginning a residency at the Kelly-Strayhorn to work on "Mayhem & Majesty," a new production that will premiere in March after a free work-in-progress preview on Nov. 20-21. O'Hearn says the work will be a departure from its last piece, "Astro-Rama," performed during a memorable weekend in the summer of 2008.

"We're freeing ourself up to do intuitive work, real devised theater, as the Brits call it, and so the whole show is bouncing off the simple reality and the interesting aspect of music being made and heard -- live. And to play with all of that we're going to be playing with a lot of technology like we like to do, so there will be live feed video and green-screen work and robotic props. It's a show where we'll be inventing individual scenes like we did with 'Big Smorgasbord' rather than starting out with a big strong narrative thread. We're playing and making our decisions intuitively the way Jackie and I have always been prone to doing."

So, question to ponder this weekend: Would you trust your children to spend the day with Squonk Opera?

They'll come out the other end of it more creative, if a bit more twisted, having been exposed to Pittsburgh's minstrels of mayhem.

More info at www.kelly-strayhorn.org.

People wearing creepy Victorian clothing and those gas masks so prevalent during the G-20. That's a pretty scary combo and there's a cool name for it: Steampunk!

It can be experienced in the flesh at The ScareHouse in Etna, one of America's most frightening Halloween attractions, according to the Travel Channel, which surely gets around. The ScareHouse's latest addition is Rampage, a fantasy/sci-fi genre set in the Victorian era that goes well beyond horror movie cliches.

"We wanted to create a world in which all of the dark and messy secrets of a so-called civilized world were suddenly unleashed all around you," says creator Scott Simmons.

Yikes.

"It's very intense to journey through the dark when you can see all kinds of maniacs and monsters looming above you."

True.

"More than a few people thought we had lost our minds because they only saw steampunk as being a very cultured and kind of refined genre" -- and most people had no idea what it was -- "but we saw great opportunity to create all kinds of conflict and contrast. Working in a purely fantasy environment allows you the opportunity for endless ideas and creative freedoms. You can create scenes with a giant eyeball, killer robots and steam-powered machine guns, and somehow it all makes perfect sense. I feel like we're creating our genre this year. We're mixing steampunk with George Orwell and H.P. Lovecraft, along with machine guns and killer robots."

It was a lot of work, Simmons says, particularly since "it's not like you can run down to local Halloween store and ask to see their steampunk section."

The world's not that messy yet.

• Also in the haunted house realm, The Nightmare at Station Scare, or whatever it was called, was dead to rights for two years until the Pittsburgh Concert Group put new life into the Amphitheatre at Station Square. Now the ghouls are back, populating a haunted mansion and a haunted stage, which stars the ghosts of performers past, plus a cemetery walk-through, "Drown the Clown" dunk tank and a collection of local and national vendors. It's not recommended for ages 13 and younger.

• As the song says, Bela Lugosi's dead, but vampires are still de rigueur, thanks to "Twilight," "The Vampire's Assistant" and other fanged projects. At Castle Blood in Washington County, the theme is Night of the Vampire, with a 30-minute guided tour that explores vampire legends. Another new feature is The Hollow, described as their take "on the pumpkin and cotton field gone bad."

• Kennywood didn't add anything new to Phantom Fright Nights, but judging by the hour-long lines to get on the rides, it didn't matter. Teens love Fright Nights and this weekend is the last ride.

Halloween wouldn't be the same without science. We'd have no Frankenstein, no alien creatures, no Invisible Man, no mass-produced candy bars. So how 'bout some love for the Carnegie Science Center, which celebrates Halloween Saturday with Spooky Science?

The kids can trick-or-treat indoors, make glow-in-the-dark slime, create grossly realistic wounds and piece together skeletons in a giant puzzle.

It wraps up with a Family Hallo-ween Laser Show in the Buhl Digital Dome. Beginning at 7 p.m, laser show tickets are $8; a $5 add-on price is available for those who come to Spooky Science and stay for the laser show. Members can see the laser show at no cost.

• How would a zombie go to the prom? Very slowly and rather sloppily, we suppose. Find out Saturday at SPELL, Persad Center's annual Halloween extravaganza. The Zombie Prom at 5996 Penn Circle South (third floor) in East Liberty will feature food and drink, and entertainment provided by VIDA the Singing Diva, Pitt Dancers, Jeremiah Clark and DJ Trevor. Everyone who attends will automatically be entered in the SPELL Costume Contest. It runs from 7 to 11 p.m. Proceeds from the $50 tickets benefit the Persad Center, a counseling center specifically created to serve the gay, lesbian, bisexual and transgender community. Go to www.spellpgh.org.

• Name your favorite dead celebrity. OK, that's your costume for Halloween at the Hazlett: A Day of the Dead Celebration Friday night from 8 p.m. to 2 a.m. The first Hazlett fundraiser, presented by Port Authority, WYEP and WHIRL Magazine, features free food by Bob Sendall/All in Good Taste Productions, Latino libations, a costume contest and modern dance performances by NAKA Entertainment, Greer Reed-Jones/AWC Dance Ensemble and Attack Theatre, plus Vanessa German, DJ Soy Sos and the DJ crew Humanaut. After the performances guests can descend into the basement for a mock cemetery for a traditional Day of the Dead procession. Admission is $25 advance; $35 at the door. VIP admission is from 8 to 10 p.m., costs $75 and includes premium food and drinks in addition to private performances by DJ Ray Lugo. Free valet parking will be available all evening. For tickets visit www.showclix.com/shows_listing3.php?event=4477.

• A haunted Victorian estate is the setting for "Evaline 2009: A Space Odyssey" on the backstreets of Bloomfield. Evaline Industries has created this haunted space-themed party on Halloween night at 426 S. Evaline St. with food and beverage, DJ dancing and music by Brooklyn's Low Water, Evaline house band The Replicas and Meeting of Important People. It begins at 10 p.m. Admission is $20; 21+. Go to www.fnipgh.com/evaline.

• Elise's Playground explores the erotic side of the haunted weekend with "A Halloweeen Eve Ball" Friday at Belvedere's in Lawrenceville featuring DJ Dale Cooper spinning dark '80s, synthpop and industrial, performances by Bridge City Bombshells, Sachem Orenda & The Molecule Party and Miss Elizabeth Couteau & the Playgrounds' eccentric playmates. It begins at 10 p.m. $10 before 10 p.m.; $13 after. www.elisesplayground.com.

• The 31st Street Pub, home to the skull room, will open its doors Saturday night for a Super-Sick Totally Tasteless Halloween Spectacular featuring horror-sleaze-rock band Chip DiMonick, B-movie rockers The Forbidden 5, The Botched (billed as the Worst Band in Pittsburgh!) and The Bloody Seamen (yuck). Additional entertainment will include "Lucky the Pain-Proof Man" injuring himself and "Burlesque girls doing things their parents would be ashamed of." It begins at 10 p.m. Attendees are encouraged to dress in costume.

• It wouldn't be Halloween without another compilation from Production Procedures Productions, which turns up this season with "7 Years Bad Luck," featuring seasonal tracks by 29 bands including Amoeba Knievel, The Fitt, the Beagle Brothers, Dave Bernabo + Assembly, Julie Sokolow, Marvin Dioxide, Buddy Nutt, Mustache Required and The House of Assassins.

There are three release shows, where the CD will be available for $5:

Tonight at Howler's Coyote Cafe: Middle Children, Amoeba Knievel and Marvin Dioxide with DJ Professor Stripey. $4; 10 p.m. 21+.

Friday at Kopecs Bar, Penn Avenue: 28 Whores, House of Assassins, Dean Cercone and Mustache Required; $4; 10 p.m. 21+.

Sunday at Belvedere's: El Grosso, Whisky Tango Foxtrot and more with DJ Taco Saurus Mex and DJ Steak Dinner. $4; 10 p.m. 21+

• Bloomfield Bridge Tavern, a Halloween haunt with beer and pierogies, presents a bill Friday at 9:30 p.m. with Lil Vampires (featuring Mark from My Prodi), Seas We Fear to Sail and Bowhunter. Admission is free.

• theCAUSE raises the Dead -- The Grateful Dead -- on Saturday with guitarist Patti Spadaro at P.D.'S Pub in Squirrel Hill at 10 p.m.

• Finally, there's the annual club show "people are dying to get into" -- Night of the Singing Dead, now in its 17th gruesome year. Sadly, there are a number of new additions, most notably Michael Jackson, who will be scarily represented. Playing the Dead celebs will be such media types as Larry Richert, Steve Hansen, Carol Lee Espy, Susie Barbour and Monty & Zeke from the Y108 Morning Show. It's at the Rex Theatre, South Side, Friday and Saturday at 8 p.m.; $13. 412-431-0700.

Doug Oster writes a blog, "Growing With Doug," exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.