Could you keep "@time" when changing the date, please?
e.g. I have the following due date (German):
8/1 2013 um 09:00
When I want to change the date to (postpone to) "9/1 2013 um 09:00" the time is not taken. The result is "9/1 2013".
I think it would be better to keep the time than to release my mouse for typing the same time again.
GTD also means for me being effective when using tools, mouse and keyboard (or a touch interface).
What do you think?