The keepalive decode and standby status ack used 946080000000 as the
Postgres-to-Unix epoch offset (ms). That value is 1999-12-25, seven days
short of the real Postgres epoch (2000-01-01 = 946684800000). Replace both
literals with a shared POSTGRES_EPOCH_MS constant matching pgoutput.ts.
The affected timestamps are observability-only: the decoded keepalive
timestamp is unused by consumers, and the encoded standby-reply timestamp
only surfaces as pg_stat_replication.reply_time. WAL feedback is driven by
the LSN bytes, so slot advancement is unaffected.
Matt Aitken
1fcb4a7f65