The traditional East Asian calendars divide a year into 24 solar terms (節氣). Lìchūn ( pīnyīn), Risshun ( rōmaji), or Ipchun/Ripch'un ( romaja) is the 1st solar term. It begins when the Sun reaches the celestial longitude of 315° and ends when it reaches the longitude of 330°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 315°. In the Gregorian calendar, it usually begins around February 4 and ends around February 18 (February 19 East Asia time). It's also the beginning of a Sexagenary cycle.