Validates a Unix timestamp (seconds) for SermonAudio scheduled publish.
Past times are allowed (SermonAudio publishes immediately). Only the upper bound is enforced.
Parameters
publishTimestamp: number
Unix timestamp in seconds.
nowMs: number = ...
Reference time in milliseconds.
Returns string
Error message when invalid, or undefined when valid.
Validates a Unix timestamp (seconds) for SermonAudio scheduled publish. Past times are allowed (SermonAudio publishes immediately). Only the upper bound is enforced.