A Birthday by Christina Rossetti is a poem that explores the themes of time, mortality, and the beauty of nature. The poem is written in a reflective and introspective style, and it uses vivid imagery to create a sense of wonder and nostalgia. The poem is divided into three stanzas, each of which focuses on a different aspect of the birthday experience. The first stanza describes the excitement and anticipation of a birthday, while the second stanza reflects on the passing of time and the inevitability of death. The third stanza ends on a note of hope and renewal, as the speaker resolves to embrace the future and all that it may bring.