CRM : Modify contact note date?

CRM : Modify contact note date?

I just imported my list of contacts in Zoho CRM.
I would like to add notes in those contacts in order to keep a track of differents events about them (where I met them, on wich projet, what did we said,...).
So I'm gonna add notes to each of those contacts.
But these notes allways have today's time.
How could I modify this time (inorder to move it in the past, when the corresponding event happened)?
Thks
Fabrice