Well js files are loaded and CB is excluded from jch_optimize, and I have always this problem with date field.
I guess it's css related but cannot find where.
I've no idea what's causing it specifically, but it's something in JCHOptimize. I did not create their extension so it's best if they take a look and maybe able to suggest what could be happening. If you disable CSS/JS compression for CB only does the issue resolve?
Hope you will have time soon to make this little plugin to have all stylesheets within one, IE 9 will be supported for a while by Microsoft
Please understand there is no guarantee we'll ever make such a plugin. I simply stated it's something I'll be looking into, but certainly don't want you to wait and get your hopes up if nothing comes of it.