A relatively simple children’s book gets pumped up into epic mayhem in “Alexander and the Terrible, Horrible, No Good, Very Bad Day.” Apparently the filmmakers felt it necessary to live up to the humongous title.

Published in 1972, Judith Viorst’s “Alexander” has charmed readers ever since. It’s about the travails of a kid who wakes up with chewing gum stuck in his hair — an early sign that everything is going to go wrong for him on this particular day.

Alexander (played by Ed Oxenbould) is having his birthday today, not that anybody else in his family seems overly interested — as usual. His unemployed dad (Steve Carell) has a job interview, mom (Jennifer Garner) has a big presentation at work.

There’s an older brother (Dylan Minnette) anticipating prom night, and an older sister (Kerris Dorsey) debuting in the school production of “Peter Pan.” Everything’s going to go wrong for them, too, from the brother’s powder-blue prom tuxedo to the sister’s tipsy overdose of cold medicine.

There’s also a baby mixed in there, although he comes out relatively unscathed.

Some of the appeal of the book comes through in the enjoyable early reels: Everybody’s had bad days, and Alexander just needs to learn that this happens for no reason sometimes, and maybe a bad day just lets you appreciate the good days.

So far, so good. But the bigger the disasters become, the less charming the whole thing gets. Car crashes, onstage meltdowns, Dad catching on fire at a Japanese restaurant — stuff really goes off the rails.

Because Carell and Garner can be quite funny in their reactions to disaster, some of the slapstick pays off. Even the Japanese restaurant scene.

Overall, though, I expected more from director Miguel Arteta, whose films (such as “Youth in Revolt” and “Cedar Rapids”) have been quirky and distinctive. Arteta brings a good sense of comic timing to the festivities, but overall the thing is truly mild.

One good surprise: Dick Van Dyke pops up in a cameo as himself, doing a public reading from a children’s book that has a fatal typo he hasn’t been warned about. He carries the spirit of kid movies from the past, which this one can’t quite live up to.

“Alexander and the Terrible, Horrible, No Good, Very Bad Day” (2 1/2 stars)

An expansion of Judith Viorst’s much-loved children’s book, in which a boy’s bad mojo affects his entire family. Some agreeable silliness from Steve Carell and Jennifer Garner, although the film doesn’t have much charm.

Rating: PG, for subject matter

Showing: Alderwood Mall, Everett Stadium, Galaxy Monroe, Marysville, Stanwood Cinemas, Oak Tree, Pacific Place, Woodinville, Blue Fox Drive-In, Cascade Mall, Oak Harbor Plaza.