The offset() family of functions provided to Cloud Datum Stream expressions are useful for calculating differences between datum over time. Currently they impose a limitation in that they can only "see" datum that are present in the active cloud service request.

For example if a Cloud Datum Stream requests a time range on Jan 1 2025 between 12:00 - 12:30, and the response includes 30 datum exactly on each minute in that range, the datum at 12:00 has no offset(1) when it might be expected to return a datum at 11:59 stored on a previous request.

This ticket is to enhance the offset() functions so that they can query data previously stored in SolarNetwork to satisfy the function.