A thought: Perhaps the BC2300 was set to RECORD rather than PLAY at 1230hrs every day?
This is a bit more complicated to clear, because there are more options depending on whether you are recording to A.TAPE or V.TAPE - and of course this assumes that system was part of an interconnected system in the past.
I am guessing slightly, but I think to clear an A.TAPE recording timer, it would be as follows:
PROG
PLAY (Edited - I got PLAY and DOWN reverse when first posted, sorry)
DOWN
STATUS
CLEAR
And to clear a V.TAPE recording, it would be:
PROG
PLAY
STATUS
CLEAR
I have tested the above A.TAPE recording timer clear with my BC9500, and that sequence works. It seems to function the same on the BC2300, but obviously doesn't find anything when I press STATUS.