A Note About Date Ranges

Types of data that are date ranges are serialized to JSON as an object with bounds:

{
  "bounds": "[)",
  "end": "2025-09-16",
  "start": "2025-09-15"
}

A date of service may span multiple days (for example, a hospital stay), so it's stored as a range.

In text form:

Symbol	Meaning
[	Inclusive lower bound
(	Exclusive lower bound
]	Inclusive upper bound
)	Exclusive upper bound

For more details and examples, see the PostgreSQL documentation: Range Types — Inclusivity.