xún​shǒu

start of a ten-day period

旬首 xún​shǒu
start of a ten-day period
the first day of a ten-day period in the lunar calendar or a traditional cycle of days
start of a decade
the first year of a decade in a person's age, such as the 51st, 61st, or 71st year
head of a xun
the first of the ten Gan-Zhi (Stems-and-Branches) combinations in a ten-day cycle, used in divination and traditional calendar calculations