assert(Month.jan.quarter == Quarter.q1);
assert(Month.feb.quarter == Quarter.q1);
assert(Month.mar.quarter == Quarter.q1);
assert(Month.apr.quarter == Quarter.q2);
assert(Month.may.quarter == Quarter.q2);
assert(Month.jun.quarter == Quarter.q2);
assert(Month.jul.quarter == Quarter.q3);
assert(Month.aug.quarter == Quarter.q3);
assert(Month.sep.quarter == Quarter.q3);
assert(Month.oct.quarter == Quarter.q4);
assert(Month.nov.quarter == Quarter.q4);
assert(Month.dec.quarter == Quarter.q4);