Muggles and wizards alike are invited to celebrate the release of the sixth Harry Potter book, "Harry Potter and the Half-Blood Prince," by Scottish author J.K. Rowling, at numerous parties in local bookshops and the Central Library on Friday, July 15.

Although Potter parties start earlier on Friday, booksellers are unable to sell the book until 12:01 a.m. on Saturday.

The Milwaukee Public Library's "Late Night With Harry Potter" runs from 9 p.m. until 11:30 p.m. at the Downtown Public Library, 814 W. Wisconsin Ave. Free activities include a Wizard Show, fortune telling, potion-making, crafts, refreshments, carriage rides in a horse-drawn carriage (limited supply), a screening of the first Harry Potter film, free prizes and more.

"It's a family event with fun for everyone," says Lorelei Starck, communications director for the library.

At midnight, 300 copies of the book will be available for checkout and many more copies will be available to buy.

All Schwartz Bookshops will host a Potter party featuring activities and refreshments starting at 9 p.m. The new Schwartz Bookshop in Bay View, 2262 S. Kinnickinnic Ave., will open for the first time at 11 p.m. to celebrate the release of the book and to honor the birthday of the late David Schwartz who would have been 67 years old.

Costumes are optional, but encouraged at all of the Schwartz parties, and books may be reserved in advance by calling the shop.

Border's Books will host a "Midnight Madness" party. Wizard-related activities kick off at 9 p.m. The first 50 families to check in at the downtown Milwaukee, Fox Point and Glendale locations will each receive a free Paradise Landing Family Day Pass.

Wauwatosa's Little Read Book, 7603 W. State St., has multiple reasons to celebrate on Friday night, including its 20th anniversary. A Potter party starts at 11 p.m. with a trivia contest, prizes, giveaways, cake, refreshments and a magic show.

Fran Gieldon, children's librarian at Zablocki Library and co-chair of the "Late Night with Harry Potter" event, says there are many reasons why the Potter series is so popular with children and adults.

"The Harry Potter books transcend any single genre description. They are fantasies, mysteries, and in many ways even realistic fiction. They are books about serious subjects written with humor. But, probably their greatest appeal is that most children and adults can identify with Harry's struggles to discover who he is and what his role in his world is," says Gieldon.