- the annual day for enrollment in the militia of all able men aged 18 to 45, according to a law established in 1792 and in effect until after the Civil War.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for muster day
And now comes dinner,—a most important feature of muster-day.
A very different affair is the "muster-day" of the early fall, before the cold days and nights have come to stay.
It is Sunday, and muster-day, and the Alabama has once more been put in perfect order.
Quarterly training or muster-day became an occasion more noted for the rum then consumed than for the drilling done.The Old First Massachusetts Coast Artillery in War and Peace
Frederick Morse Cutler
As a child, I loved to see the colors of the holiday-soldiers flapping in the wind and flaunting in the sun on "muster-day."