Does anyone know if there is a Memo or Reg on who enters the training schedule into DTMS, ie AGR or M-Day responsibility?

thats what my job is as training NCO

If you have an AGR training NCO, I would think it would be in the job description. Training is also mentioned in the job description of the Unit Administrator. I do not know of any formal regulations that specify responsibility. At any point the commander can appoint someone as an additional duty or any Soldier with access can do it.

I am not sure why you would want an M-Day Soldier to input a training schedule to begin with. Not that they couldn't do the job but if there are questions in regards to support required or for planning purposes to be available wouldn't an AGR better suited for that. I think that M-Day leadership should absolutely have access to make sure that it is done the way they would want though.