A customer has an application that allows picking arbitrary date ranges at a day level, but shows a chart of month-based aggregates. If a user picks start/end dates on the first of a month, the month results work as expected, but if they pick something in the middle of a month, then either no results or results for an entire month are shown.

What they would like to be able to show is "partial" results for the first/last month in the selected range, such that just the results for the days within that month are aggregated for those month's result buckets.

For example, for a date range of 15 Jan 2019 to 15 Mar 2019 and Month aggregation they would like to see 3 results, covering these ranges:

1. 15 Jan – 31 Jan
2. 1 Feb – 28 Feb
3. 1 Mar – 31 Mar

So result #2 is a "normal" full month value, while results #1 & #3 represent "partial" month values.