"the greatest day of the whole year"

Baltimore Oriole, Charles River Peninsula, Needham, MA

...[T]he greatest day of the whole year is in early May when the season is well established, when the apple blossoms are opening....On this day, not far from the 8th of the month, the Baltimore oriole makes his dramatic entrance into New England. On every hand, in our orchards, among the high branches of our roadside elms, the little trumpeter is heard blowing his tiny bugle; all out-of-doors is animated by his buoyant personality.
--Arthur Cleveland Bent

The females are also back, singing their charming songs.

And the orchard orioles are still battling for the sole female.

And the rose-breasted grosbeaks and bobolinks (not shown) are singing.