WDJZ is Daytime Only to protect WCKY. They also have a "dogleg" tower array, creating a very deep null toward Elizabeth NJ, to protect the 1530 there. (Interesting trivia: WJDM, 1530 in Elizabeth, NJ was the FIRST station in the US to get an Expanded Band frequency, on 1660. They were supposed to SHUT DOWN the 1530 after 5 years. They didn't. They sold it, instead.)
For MANY YEARS, 'DJZ was signing on in winter, well before sunrise, with much more power than they are allowed. (50 watts from 6am to sunrise, but they appeared to be using full day power.) Then they'd stay on the air well past their legal sign-off. For some time, their air staff would punch the transmitter back up, after the automation shut it down. I heard that their CE "fixed" that problem, so they CAN'T override the sign-on, low power, and sign-off anymore. Kudos to him!
As for their format... they are the absolute definition of "Dollar-a-hollar" radio. If you have money, they don't care what you have to say, you're on the air. Makes for a less-than-listenable overall format.
When they first signed-on in the late 1970's, they had a "standards" format. Then they tried being "full-service" for a while. I don't know how well they'd make it with those formats, though, since they are limited to daytime only.
Despite being a Daytimer with ZERO pre-sunrise and a PITTANCE for post-sunset, WFIF does well with their all-talk Christian format. Why? Because they hold their program providers to high standards, so that the programming is quite consistent in its content and quality. WDJZ's programming is not. At all.
I am honored to say that I worked for WFIF for 20 years.

I was their CE for the last 15, and Music Director & Production Manager, for the last 17.
