Noun
(obsolete) The work done in a day; a day's work. [10th–19th c.]
(obsolete) The amount of land that can be worked in a day. [14th–17th c.]
Work carried out or paid for on a daily basis; day labour. [from 16th c.]
Work done during the day; specifically, the cover-work carried out by someone involved in intelligence work, as opposed to their secret activities.
Source: en.wiktionary.org