Time's fool is referring to any concept that becomes lost in time. Love is an intangible and uncontrollable feeling, yet is felt instantly and does not waste time to be present.
The literary device used in these lines is Personification.
The personification is a figure of speech in which a thing is given human attributes. The non-human objects are portrayed in such a way that we feel they have the capacity to act like human beings. This device makes the piece more interesting to read and makes it more sensitive to the reader.
