What musical time period was Gustav Mahler from?

Gustav Mahler was a composer of the Late Romantic period, specifically the Late Romantic/Post-Romantic era. This period roughly spans from the late 19th century to the early 20th century (approximately 1890-1910).

While his music shares elements of Romanticism, it also pushes the boundaries of the genre, foreshadowing elements of 20th-century musical styles.