From The Collaborative International Dictionary of English v.0.48 [gcide]:
Canicular \Ca*nic"u*lar\, a. [L. canicularis; cf. F.
caniculaire.]
Pertaining to, or measured, by the rising of the Dog Star.
[1913 Webster]
Canicular days, the dog days, See Dog days.
Canicular year, the Egyptian year, computed from one
heliacal rising of the Dog Star to another.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
canicular
adj 1: of or relating to the dog days of summer; "the canicular
heat of the Deep South"
2: relating to or especially immediately preceding or following
the heliacal rising of Canicula (the Dog Star); "canicular
days"