I'm going to graduate in Computer Engineering in 12 months, and I've started sending a few applications for full-time jobs outside of the area where I'm currently studying (where applying for internships wouldn't make sense). However, most places I've applied at wanted to fill a position ASAP, which prevented me from even getting an interview (which some of them outright stated in their negative responses to me).
With that in mind, when would be the ideal time to start sending out applications that won't get lost in a void? Alternatively, how to recognize the places that aren't trying to fill something right now when applying, so I won't waste time writing cover letters for those?