Timekeeper Time Zone Converter

This tool converts a specific ISO 8601 timestamp into a target IANA time zone and reports the converted ISO timestamp, time zone offset, and whether the result falls on a business day. It accepts iso_time (required ISO 8601 timestamp), target_zone (required IANA time zone identifier), and source_zone (optional IANA time zone for iso_time when no offset is present, defaulting to UTC when omitted). The worker must transform these inputs into a response whose JSON structure and field types strictly validate against the system-provided structured output schema, without adding extra keys or nulls not allowed by that schema.