The Due Time field value related to event record is always showing as 12:00 when it is added in the group row section of the report builder instead of the actual value derived from the StartDateTime field.
This is expected behavior. The Due Time field in the Tasks and Events report type is derived from the ActivityDate field rather than the StartDateTime field when used in grouping. Because ActivityDate is a date-only field, the time component defaults to 12:00 (midnight or noon depending on locale). As a workaround, consider adding the StartDateTime field as a column rather than using Due Time as a group row.
Other Reference: https://developer.salesforce.com/docs/atlas.en-us.object_reference.meta/object_reference/sforce_api_objects_event.htm
004518591

We use three kinds of cookies on our websites: required, functional, and advertising. You can choose whether functional and advertising cookies apply. Click on the different cookie categories to find out more about each category and to change the default settings.
Privacy Statement
Required cookies are necessary for basic website functionality. Some examples include: session cookies needed to transmit the website, authentication cookies, and security cookies.
Functional cookies enhance functions, performance, and services on the website. Some examples include: cookies used to analyze site traffic, cookies used for market research, and cookies used to display advertising that is not directed to a particular individual.
Advertising cookies track activity across websites in order to understand a viewer’s interests, and direct them specific marketing. Some examples include: cookies used for remarketing, or interest-based advertising.