Oh, if it be to choose and call thee mine, love, thou art every day my Valentine!

The speaker frames “Valentine” not as a single calendar-day token but as a continual choice: to “choose and call thee mine” is to renew love daily. The exclamation suggests ardor and a playful, courtship idiom, but the logic is serious—true affection is measured by constancy rather than ceremony. By addressing “love” directly and elevating the beloved to “every day my Valentine,” the line turns a social custom into a private vow, implying that devotion should outlast the holiday that symbolizes it.