Well, there's this pop song called More Today Than Yesterday (click) by Pat Upton, recorded by Spiral Starecase (sic) a one-hit-wonder from around 1969, and covered by lots of other performers, including Andy Williams. It contains the words:

Oh, I love you more today than yesterday
But not as much as tomorrow
I love you more today than yesterday
But, darling, not as much as tomorrow.

Is that the one you had in mind?