1
general::
Also, all in the day's work. Expected and normal, as in He said I bad to finish these reports by five o'clock? all in the day's work. This phrase is sometimes used as an ironic comment on an unpleasant but not abnormal situation. The expression possibly alludes to the nautical term day's work, defined in 1789 as the reckoning of a ship's course during the 24 hours from noon to noon. [c. 1800]
American Heritage Idioms
2
general::
Phrase(s): all in a day’s work
part of what is expected; typical or normal. • I don’t particularly like to cook, but it’s all in a day’s work. • Cleaning up after other people is all in a day’s work for a busboy.
McGrawhill's American Idioms And Phrasal Verbs