January 20, 2011 5:10 PM PST
I think what you're forming with "have" is the present-perfect tense. "Have", when placed before a verb (+ed), implies an action done in the past but possibly still going on. E.g.
"Jon has studied as a student for four years."
"Jon studied as a student for four years"
(The first one implies that he still is a student, while the second implies he's no longer a student)
More info: http://www.eclecticenglish.com/grammar/PresentPerfect1A.html
As per the info on that page, the present-perfect is also used to talk about experiences ("I have worked as a volunteer") and past action that has a result in the future/now, just like your example:
"You have submitted a proposal today"
On it's own, there's little consequence to the proposal being submitted, but what might follow is a consequence such as:
", and are therefore relieved of duty."
Depending on the context, you might also add "already" before "submitted".
It would seem that your second sentence ("You have submitted a proposal today") is grammatically correct, although a little context would help in determining whether forming the present-perfect is required.
“You have submitted a proposal on the 3rd of November 2010?
... seems incorrect. The submission of the proposal was not really recent enough to warrant usage of the present-perfect tense. In this case, this would be best:
“You submitted a proposal on the 3rd of November 2010?