A new field called Send time has just been added to the Mailchimp connector. Funnel use this field to attribute Mailchimp values to a date and now it's represented as its own field too.
This was added to the connector for the reason that this field contains a time stamp as well, such as: 2020-11-19T23:05:11+00:00.
If you have an already connected Mailchimp data source, then 3 months of data will be imported by default. If you need more historical data, please get in touch with firstname.lastname@example.org and we'll be happy to help!