The English idiom is "to seize the moment" is pretty close to the Latin "Carpe Diem" and means to take that moment and do whatever you are meant to do at that moment and not put it off. It is a set phrase and therefore it doesn't change.

Time is a large, abstract concept. You cannot seize time; in this context "time" refers to everything that has happened in the past and everything that ever will happen. Seize the time doesn't really make any sense. However, a "moment" is a fleeting occurence in time; so at this moment I am writing you this comment. To seize the moment is to take control of what is happening in front of you right now, often in an accepting fashion.