A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

day-man • man of the day
day-man —a man who does work during the day or on a
day-shift: A company taxi is usually driven by both a day-
man and a night-man.
man of the day —
1
. an outstanding man of his time: Hamsun
was a man of the day, who, despite his age, strove to make his
ideal into a reality. Cf.: man of the year — a man who has done
the most to influence the events of the particular year (as featured
by the U.S. newsmagazine Time): Mikhail Gorbachev was the
man of the year for 
1
987, an eminently defensible choice….
2. (Military) a soldier on duty for the day: Cooked food was
“dished out” by the orderly men of the day.
day off • off day
day off —a day away from work, school, etc.: The bus-driver
spends his “day off ” in driving on a pal’s bus, on the box-seat
by his pal’s side.
Note: 
The expression is not equivalent in meaning to the phrase
day out
—1. a day away from home when one is free from duty:
Ollie just loves going to shows and he thoroughly enjoyed his
day out. 2. a servant’s free day: When it is the maid’s day out,
Jack insists on helping with the dishes.
off day —1. a day when one does not feel fit or does not per-
form well: The bartender could have smiled a little but maybe
it was his off day. 2. = day off 1: I could also change which day
was my off day to line up with friends’ birthdays or other cel-
ebrations.
Note: 
The expression does not correlate in meaning with the
phrase far-off day—a day remote in time: On that far-off day I
lay on the rocks and listened to the deep rhythm of the Atlantic.
day order • order of the day
day order —(Stock market) a customer’s order that expires at
the close of the day: A day order is canceled if it is not executed
before the close of business.
order of the day —
1
. an agenda: The order of the day will be
issued each day with detailed information on Conference. 2.
a statement issued by a commander to his troops: In his Order
of the Day Mannerheim thanked the civil guards for their
work for the benefit of the country. 3. fixed and regular way
of doing things: He was sick of living on literary lunches where
nouvelle cuisine seemed to be the order of the day.