You need to be upfront about the schedule you're willing to work. As you know, you are interviewing them as much as they are interviewing you. This distinguishes you from the herd as a viable candidate simply due to the fact that you're both after the same thing, a good fit. Interviews are an excellent time to uncover what's expected. Take notes and follow up with questions. When possible, have a notebook or folder containing all your resumes and cover letters that you've sent off to other employers, divided into sections, with notes from each interview in each separated tab. This will not only advertise you are playing the field but are approaching it with an organized systems approach, where you are scaling what each job has to offer, as well as respectfully exhibiting your interviewing skills.

"I am available around the clock, and ready for anything."