An infinitive is the verb form using the word "to," as in "to eat," "to play," or "to read." An infinitive phrase includes the base infinitive plus other modifiers or complements. An infinitive phrase can often be used as the subject of a sentence because it refers to the act itself rather than doing the action. In this case, "to make it to the end of the day" is an infinitive phrase acting as the subject of the sentence.
