When?

semester
one of two divisions of an academic year
 
summer school
an academic session during the summer; usually for remedial or supplementary study
 
Christmas Eve
the day before Christmas
 
lactation
the period following birth during which milk is secreted
 
downtime
a period of time when something (as a machine or factory) is not operating (especially as a result of malfunctions)
 
split shift
a working shift divided into two periods of time with several hours in between
 
Victory Day
the day of a victory
 
Italian Renaissance
the early period when Italy was the center of the Renaissance
 
Fast of Gedaliah
(Judaism) a minor fast day on Tishri 3 that commemorates the killing of the Jewish governor of Judah
 
Av
the eleventh month of the civil year; the fifth month of the ecclesiastical year in the Jewish calendar (in July and August)
 
Eastertide
the Easter season
 
quarter day
a Christian holy day; one of four specified days when certain payments are due
 
stretch
an unbroken period of time during which you do something
 
1930s
the decade from 1930 to 1939
 
contemporary world
the circumstances and ideas of the present age
 
seedtime
any time of new development
 
Lententide
a period of 40 weekdays from Ash Wednesday to Holy Saturday
 
birthday
an anniversary of the day on which a person was born (or the celebration of it)
 
Quadrigesima Sunday
the first Sunday in Lent
 
growing season
the season during which a crop grows best
 
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