Here is a feature request, I entered quite some time ago. I now want to discuss it and maybe find some followers on the theme:
I am a heavy user of adding tasks per email. Over time I realized, that entering a specific date is a bit cumbersome. Say I want a task to begin on November, 30 I add ">2011-11-30". It would be more convenient to have a shorter phrase like ">30", meaning the next day being the 30th of a month. That would be much shorter, less error prone, and perfectly in line with phrases like ">tue", meaning next Tuesday.
One step further you might even allow ">Sep" standing for the first day in September.