Do I have an obligation to tell my ex-husband when I am getting married?

I am getting married in less than two weeks. My ex-husband knows that I am engaged and have been for a while, but he does not know the wedding date. He has done an excellent job of training our children not to say a word to him about me or their life with me, so I know they won’t share the news. Do I have an obligation to tell him the date or can I just let him find out in his own time?