by the end of sth
prep. phr..prep. phr.. This phrase marks the latest time something will happen or be finished. It means before or at the very end of a period like a day, week, or year.
prep. phr.. A prepositional phrase indicating the terminal point in time by which an action or event is completed or occurs.
Please finish your homework by the end of the day.
By the end of the month, all employees must complete the mandatory safety training.
The empire, having overextended its resources and alienated its allies, was facing total collapse by the end of the third century.
This phrase is followed by a noun indicating a time period, such as 'the day', 'the month', or 'the year'.
Contrast with 'at the end of': 'by the end of' means 'no later than', while 'at the end of' specifies the exact point when the period concludes.
I will call you at the end of the day.I will call you by the end of the day.Use 'by' to set a deadline for an action, not 'at', which refers to the specific moment something ends.