1063: since must be an RFC3339 timestamp, e.g. 2026-08-14T00:00:00Z

since must be an RFC3339 timestamp, e.g. 2026-08-14T00:00:00Z. This is an HTTP 400: the request could not be parsed.

• Check this endpoint’s request schema in the API reference; param in the response names the exact field at fault.
• Use an official SDK, which enforces required fields and types before the call is made.