An academic quarter (German: Akademisches Viertel, Swedish: akademisk kvart (ak or aq)) is the quarter-hour (15 minute) discrepancy between the defined start time for a lecture or lesson ("per schema") and the actual starting time, at some universities in Austria, Switzerland, Estonia, Finland, Romania, Belgium, Croatia, Slovenia, Germany, The Netherlands, Denmark, Norway, Portugal, Poland, Sweden, Serbia, Italy, Israel, Hungary, Greece, and the UK.
The quarter system dates back to the days when the ringing of the church bell was the general method of time keeping. When the bell rang on the hour, students had 15 minutes to get to the lecture. Thus a lecture with a defined start time of 10:00 would start at 10:15.
Academic quarter exists to a varying extent in many universities, especially where the campus is spread out over a larger area, necessitating the need for fifteen minutes for the students to walk from one building to another between classes.
In the German university system, lectures scheduled at a certain hour, with or without the addition "c.t." (cum tempore, Latin for "with time"), usually start 15 minutes after the full hour. If this is not the case, usually "s.t." (sine tempore, Latin for "without time") is added to indicate that the lecture will begin at the exact time.
Examples
At Uppsala University, the academic quarter was officially abolished in 1982 by Rector Martin H:son Holmdahl, but has despite this still been kept unofficially at the university. In the student social life at Uppsala University and Lund University, a double-quarter (Swedish: dubbelkvart (dk) or dq) also exists. At Uppsala, it refers to the thirty minutes between the full hour and the official time when a banquet or other semi-official party or sit-down dinner starts. During this half-hour, guests mingle and make sure they know where their seats are. The official meaning of the double-quarter is though that the guests should be at the disposal of the host at the stated doubly-quartered hour.
At Lund, times are commonly stated meaning single-quartered during daytime and doubly-quartered in the evening after 6 pm and on weekends. Double-quarter means here that the event starts thirty minutes after the posted time.
At Chalmers, the academic quarter is used as the only break between classes and is placed at the end of an hour before noon. This means that classes are always posted to start on the full hour, even though they start fifteen minutes past the full hour in the afternoons.
In case, at the older universities, someone wants something to start exactly on the hour, the time is posted as "2:00 pm" or "2:00 pm sharp" as opposed to just "2 pm". At Lund, where "double-quarter" is used, exact time is posted as "sharpsharp".
At KTH student social life, exact starting times are sometimes posted as 2:02 pm, 7:07 pm etc. to differentiate from more open starting times denoted "2 pm" or "2:00 pm".
At UC Berkeley, classes generally start 10 minutes after the posted starting time. This is informally known as "Berkeley time".