Working weird hours to finish a project? Don’t make a habit of it. Drawing on its ongoing research among people who work evening and night shifts at 24-hour operations, Circadian Technologies has issued a report on the toll this schedule takes. The report says peptic ulcers are two to five times more frequent among extended-hours workers than day workers, and 11 percent suffer from sleep-related problems, vs. 2-4 percent of all workers. Extended-hours workers are twice as likely as the general population to use stimulants, and the incidence of smoking is also much higher (see chart). And given the vending-machine cuisine on which these workers often rely, it’s no surprise they have a higher incidence of cardiovascular disease. The moral of the story: Don’t quit your day job, so long as it truly is a day job.