The term "calling task" refers to a task or duty that someone feels compelled or obligated to perform. Some antonyms for this phrase include "optional activity," "voluntary undertaking," or "spontaneous engagement." These words suggest that the task at hand is not obligatory, and the individual is free to choose whether or not to undertake it. They also imply that the activity is done out of personal interest or desire, rather than out of a sense of obligation. Other contrasting phrases could be "pleasurable pastime," "recreational pursuit," or "leisurely endeavor," indicating that the individual indulges in the activity purely for enjoyment and relaxation purposes.