Definition:Time/Unit/Quarter-Year

Definition
The quarter-year is a derived unit of time. The quarter-year is defined as:
 * $91$ days

or
 * $13$ weeks of $7$ days each.

Note that a quarter-year is not actually equal to $\dfrac 1 4$ of a year: $\dfrac {365.2422} 4$ days is $\approx 91.31$ days.