Missing fields when importing database

Missing fields when importing database

Hello,
I've just iimporting 20,000 contacts on the "posibles clientes" module.
Everything is OK, except that on the origianl database each contact have an owner and the creation date and last modification date.

On Zoho CRM all contacts are under my name (I have administration profile) and the creation and last modification date, are all the same day of the importing process

Thank you for your help