You plan to get aggregated data by calling IoT Times Series Aggregates Service API for statistics.
APIs can return values with minute (multiple of 2), hour, day, week, month intervals.
For day-based data, you want to get the data in your local time zone not in UTC time zone.
Solution
Day based aggregates values are calculated with the Time Zone selected for the Asset.
For example, if you select America/New_York (UTC-4) for the Asset Time Zone, The Aggregate API will calculate the data from UTC 4:00.
Here is the actual returned data for the asset located in NewYork.
The Time Zone setting cannot be changed once Asset is created.
If you already have assets and timeseries data is injected, you can use hour based aggregate data for 24 hours and calculate the values for date.
The calculation code would probably not be that large.
Notes
IoT Times Series Aggregates Service