in: query
name: send_date
description: >
  Filter by ISO-8601 date or datetime, e.g.
  `{ "gt": "2012-01-01", "lt": "2012-01-31T12:34:56Z" }`
  where `gt` is >, `lt` is <, `gte` is ≥, and `lte` is ≤.
schema:
  $ref: "../attributes/send_date.yml"