behind schedule
Not having progressed as much as is necessary to meet a particular deadline. I'm so far behind schedule that I'll never get this report done by Friday. Thanks to the flu, I'm now behind schedule in my party preparations.
*behind schedule
having failed to do something by the appointed time, especially the time given on a written plan. (*Typically: be ~; fall ~; get ~.) We have to hurry and finish soon or we will fall behind schedule. The project is behind schedule by six months.