It chanceth in an hour that comes not in seven years.

An event may occur within a single hour even though nothing like it has happened for many years. A long wait does not rule out a sudden change.

The saying draws attention to the uneven timing of events: what has seemed remote or unlikely can arrive all at once. It does not say whether that event will be welcome or unwelcome.

Use this proverb when an unexpected development follows a long period without change, or when reminding someone that a quiet past does not guarantee an uneventful future. Its wording is archaic, so it suits a deliberately old-fashioned tone.