Dad is 90 and unwillingly living in an ALF. Lately he has become more cranky, miserable and complaining than ever before. He is also asking me and my brother why "it isn't March, anymore?". So, I understand he has dementia but is his bad mood necessarily related to the dementia or are his emotions valid expressions? I don't want to brush off his "bad mood" and blame it on dementia if that is not the case. Any ideas?
Or, your dad may be aware of the changes in his brain and is scared and that fear is coming out as anger and feeling crabby.
When your dad asks the question, "It isn't March anymore?" and discovers that it's actually July that might be pretty scary. I know it would scare me.
I agree with Sunnygirl when she suggested you explore some medication for your dad. Get him to the Dr. and see if the Dr. can't prescribe a mild anti-anxiety medication and/or an antidepressant for your dad.
Of course, maybe you dad has valid complaints. I'd see what he is upset about and try to fix it, if it's an actual problem. See if he isn't getting the foods he wants or his clothes are not comfortable. Try to honor his wishes, with the understanding that they may be his dementia at work.