I am planning out a hit counter, and I plan to make many report queries to show number of hits total in a day, the past week, the past month, etc, as well as one that would feed a chart that shows what time of day was most popular, within a specific date range, for a specific page.
With this in mind, would it be beneficial to store the DATE in a separate field from the TIME that the hit occurred, then add indexes? I would be using a where clause with a range (greater than x and less than y) for some of these queries. I do expect to have queries that ask about both the Date and the Time, such as "within the past 6 months, show me number of hit grouped per hour of the day."
Am I over complicating it? should I just use a single DateTime2(0) field or is there some advantage to using two fields for this?
I think you are bordering premature optimization with this approach.
Use Datetime. In due time (i.e. after your application has reached Production and you have a better idea of the actual requirements and how it performs) you can for example introduce views to aggregate your data in a way that proves more useful for any reporting/querying you have to perform frequently.
In the most extreme case you can even refactor your schema and migrate everything from Datetime to two distinct fields, but I doubt this will prove necessary.