Grade: F

The third week of Lent isn’t a bad time for Miramax to be releasing a movie about a young man who determines to give up something hard for him to do without, as is customary during that pre- Easter season. But “40 Days and 40 Nights” is surely a peculiar way to realize that scenario. It’s a remarkably sniggering, tawdry sex comedy that blithely trashes Catholicism in particular and good taste in general–a virtual parade of boner jokes, masturbation interludes and Viagra gags so gross and smutty that perhaps a trenchcoat should be required apparel for every audience member.

Matt, the young man in question, played by the apparently ubiquitous Josh Hartnett (the picture was shot after “Pearl Harbor,” but he looks like his old gangly self, not nearly as buffed-up as in that picture) decides to eschew premarital sex for Lent–not, of course, because he thinks it might just be wrong, but because his bitchy girlfriend Nicole (Vinessa Shaw) has dumped him and he thinks that a bout of abstinence might cure him of his obsession with her. Once it sets up this dumb premise, Robert Perez’s script does precisely what you would expect with it. Shortly Matt meets Erica (Shannyn Sossamon), a perfect girl with whom he can now have only a chaste relationship for more than a month. And of course he has a bevy of moronic buddies, led by hyper roommate Ryan (Paolo Costanzo), who ruin his chances with her by putting up a website called “The Vow” which invites betting as to whether Matt will be able to keep his pledge for the full forty days (and thereby encourages beauteous babes to throw themselves at him). (It’s a particularly outdated element of the movie that the hero, and his pals, all work for a dot.com website-designing firm–something that might have seemed plausible at the end of 2000, when the picture was shot, but now comes across as ancient history.) There’s also a horny middle-aged boss (Griffin Dunne) who sees Matt’s vow as a clever ploy to increase female interest, and decides to try it himself, with predictably dire results. Vinessa re-enters the plot toward the close and provides a final obstacle for Matt and Erica to overcome (oddly enough, her intervention involves Hartnett in a peculiarly unpleasant bondage scene not unlike the one he played in an episode of the short-lived American version of the “Cracker” TV series), but–as if there were ever any doubt–everything works in the end, so to speak.

The only thing that mitigates the awfulness of “40 Days” at all is that the leads are reasonably engaging. Hartnett doesn’t seem comfortable doing an aw-shucks Jimmy Stewart routine, and when he’s required to stumble, hem and haw he seems ill-at-ease, but he’s still an agreeable low- key fellow. Sossamon is ingratiating, too, if more than a bit pallid. Unfortunately, from that point it’s a woeful tale. Constanzo, playing virtually the same role that Michael Maronna–the Bagel Guy here–had in “Slackers,” is just as smarmy and insufferable as his cast-mate was in that stinker, and with her shrewish vamping Shaw is unendurable. (Everyone describes her as incredibly hot, but the supposed attraction is frankly inexplicable.) Particular sympathy is due to veterans Dunne, who has to endure a truly grotesque bathroom scene, and Barry Newman, as Matt’s lascivious father. Incidentally, the treatment of Catholic clergy in the movie is truly crass, one long sneer at the very concept of celibacy. As the local parish priest, Stanley Anderson is depicted as a bumbling fool, and Matt’s brother Chris (Glenn Fitzpatrick), who’s supposed to be a seminarian, is himself obsessed with sex (an offhanded gag involving him and a nun is the nadir here).

“40 Days and 40 Nights” was directed–laxly–by Michael Lehmann, who began his career with the splendid “Heathers” and then fumbled with the big-budget Bruce Willis fiasco “Hudson Hawk” (as well as a host of lesser bombs) This new effort isn’t a travesty on quite so vast a scale as “Hawk,” but in its smaller, more intimate way it’s equally terrible.