Calculated data for multiple points

In our business, people frequently use the "Calculated Data" function to retrieve (for example) daily averages for multiple tags. When they want to do this for multiple days, a new function is required for each day (presumably requiring additional calls to the PI Server to evaluate the data). The calculated data function allows multiple data items, but only a single start time and end time. Extending the function to allow a range of start times and end times to be passed could greatly improve usability and efficiency. The AFSDK appears to have functions that can be used to calculate this. For example, PIPointList.Summaries() might be able to be used, passing an AFTimeRange and an AFTimeSpan, to get evenly spaced values in the period.