Calculate an average balance for an account.

Using this endpoint, you specify a datetime range and calculate the average balance of an account for that period. The calculation multiplies each unchanged balance by the number of days it remains constant, sums those values, and divides the total by the number of days in the selected range.

The begin_date_datetime and end_date_datetime values are interpreted in the account's time zone, determined in the following order: the account's division, its parent division, the program, and finally UTC when no time zone is available. Only the calendar date of each value is considered. The calculation period begins at 00:00:00 on the start date and ends at 23:59:59 on the end date in the time zone. The period cannot exceed 366 days, and the end date must have already passed in that time zone; otherwise, the request is rejected with HTTP 400.
Requests for the same calendar days are treated as the same calculation, regardless of the time of day provided. If a matching calculation already exists, the request is rejected with HTTP 409, and the details field contains the idempotency key of the existing calculation, which can be used with the GET endpoint.

This endpoint generates the Average balance calculated event once calculation is complete.