Ulladhu Narpadhu - Verse 15

The past and future stand (only by) depending upon the present, which remains always. While occurring they (the past and future) are both only the present. (Therefore) the present is the only one (time). [In other words, there are not three times, the past, present and future; there is only one time, the present.] (Hence) trying to know the past and future without knowing the truth of the present [that is, without knowing the truth that the present is non-existent as one of the three times, and that the sole reality underlying
the sense of present time is the ever-existing self] is (like) trying to count without (knowing the value of the unit) one.