Have a field day

Meaning

Enjoy doing something, especially with enthusiasm.

Usage

Used when people relish an opportunity to act.

Origin & History

Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.

Originally military, describing a day reserved for drills or competition.

Later broadened to mean any spirited occasion.