Yosef Karo

“ Paragraph 1 — Night is not the time for wearing tzitzit because one has minimal ability to see them. According to Maimonides anything worn at night is exempt from tzitzit even if it is typically worn during the day, and anything worn during the day requires tzitzit even if it is typically worn at it, while according to Asher Ben Jehiel nighttime clothing is exempt from tzitzit even during the night while clothes that are typically worn during the day (or during day and night) requires tzitzit even if worn at night. ”