Based on the structure of "the human season" in what why do the human seasons mentioned in the tittle differ from the seasons of the year of

In line 7 of sonnet xix by john milton, the speaker ask, "doth god exact day labor, light denied" what does his question mean a what shall one charge god to work in the dark b why must god make us suffer to work c is god trying me ? d how does god expect him to work when he is blind