one thousand days
Literal count of 1,000 days. Often used in fixed expressions like 千日手 (a drawn game in shogi that lasts 1,000 days) or 千日回峰 (a 1,000-day mountain ascetic practice).
The 1,000-day circumambulation practice is known as a severe ascetic training on Mount Hiei.
Compound of 千 (sen, 'thousand') and 日 (nichi, 'day').