Do you remember what you did on the 28th of March 2011?

Or the 4th of December 2010 for that matter.
The reason I am asking is because in police tv shows and of course in real life, the police officers are asking suspects this question.
To verify if they may be had an alibi for the time frame in which the crime happened.
And I am always stunned to hear/see the suspects recollecting the things that happened on that given date easily (in police shows anyway, I don’t know about real life police/suspects).
So, would you be able to recall what you did months/weeks or even only some days ago?
Or would you have to check your diary?
Or would you have to say tot the officers/detectives: I dunno…..?