Winter retreat (setsu ango 雪安居, tō ango 冬安居) can be translated as tranquil dwelling during the winter or snow period (an 安 - tranquil, go 居 - shelter, setsu 雪 - during snow period, to 冬 – winter). The 90-day snow retreat takes place in addition to the 90-day rain retreat (u ango 雨 安居, S. varśavāsa). These two retreats are rooted in ancient India and were later integrated into regular Zen practice, most likely by Buddhist monks in Central Asia or China. However, in modern times, the duration is adapted to the needs of the secular practitioners and lay monks . Especially European culture, which is not accustomed to the Zen Buddhist principle, forces most Zen monks/priests to keep their secular occupations, because otherwise it would not be possible for them to cover existential and practice needs, or to support the maintenance of Zen monasteries and Zendos. Yet those who have experienced the effect of intense retreats are witnesses that even a shortened retreat can catapult a man far, both in his spiritual growth and in his maturation as a human.