In Herrick's "To Virgins, To Make Much of Time," what do the virgins have in common with the flowers and the course of the day?

In Robert Herrick's poem, "To the Virgins, To Make Much of
Time," what the virgins and flowers and the sun most have in common is the fleeting time
in which they might maintain the glory of their beauty.

The
idea is a metaphor, where Herrick speaks to the swift passage of a flower's
beauty—lovely today, but faded and dying tomorrow—as well as the glory of the day, soon
to see a setting sun. This is the same message that Herrick has for beautiful young
women (the "virgins"). Experience allows older people to realize that time passes very
quickly. For the young, before they know to expect it (or because they believe life will
be different for them), the advantages of youth are gone almost
before one can appreciate having them. The comparison to flowers provides a strong
reference to outward appearance, but certainly this applies to other things as well:
physical strength, intellectual acuity, etc. And the reference to the sun compares a day
to one's life, its passage as speedy as that of a
flower.

The "carpe diem" poets, of whom Herrick was one,
drew attention to "seizing the day," living for the moment—in the
moment—so as not to miss a thing. Life, like beauty, is fleeting. So Herrick reminds
these lovely young women to live for the present moment: once gone, it can never be
retrieved.

Specifically, Herrick writes, about collecting
beautiful rosebuds (in lines 1-4), that are gorgeous today, but dying
tomorrow:

And
this same flower that smiles to-day

To-morrow will be
dying.

In lines 5-8, Herrick
now concentrates on the passing of the day, the swift movement of the sun through the
heavens. This is a metaphor for the passage of life: how quickly the sun is rising, as
in the days of our youth, to soon be on the downward arch toward sunset, which is the
same as approaching evening—or death, when compared to the lifetime of a
person.

The
glorious lamp of heaven, the sun,

The higher he's
a-getting,

The sooner will his race be
run,

And nearer he's to
setting.

Clearly, Herrick
reminds the young women that their beauty—and ultimately their lives—are filled with
promise and fullness today. However, like the flowers and the sun, which are metaphors
for beauty and life, time moves along quickly until these aspects of young life are gone
forever.