"Irregular hours" means that the schedule of work or activities does not follow a consistent or predictable pattern.
Sentences with «irregular hours»
Although they often work irregular hours, many are able to set their own schedules. (bls.gov)
Small business owners, freelancers, and people who work jobs with irregular hours often can't predict how much they'll make in a month. (mybanktracker.com)
So we can hardly blame them for waking up at irregular hours. (mumsnet.com)