on the stroke of

• at the stroke of

on the stroke of

1. Precisely at a particular time.

• at a stroke

• “on the stroke of”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “at the stroke of”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• “at/on the stroke of sth”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.