In contrary to our other data providers, MailChimp does not provide historical data. It only has current data, so you can only see how many x your emails had in total. This means that selecting a different date range does not influence the data shown for your MailChimp emails. Instead, selecting a different date range influences WHICH emails are shown. The date range is used for the "send time" of emails, so only emails sent within the date range are shown.
It is however also possible to show data for emails that were sent outside of the date range! This can be done by selecting the specific campaigns you want to show in the campaign filter.
Required campaign filter
Some of the MailChimp categories, available when selecting "Create a custom widget", require a campaign filter. These categories don't have a "sent time" available, and can therefore not be filtered based on that value. To not overload MailChimp's servers, a campaign filter is required for the following categories:
Comparison and time dimensions
Not having the ability to fetch historical data, also means there's no way to compare with a previous date range. It also removes the possibility of showing the flow of the data over time with time dimensions.
Don't know what categories are? You can read more about them here!