甲子

1. • first year of the sixty-year cycle (where each year is numbered with one of the 10 heavenly stems 天干 tiāngān and one of the 12 earthly branches 地支 dìzhī)
2. • the sixty-year cycle

Character by character

• 甲(jiǎ)first of the ten Heavenly Stems 十天干 shítiāngān
• 子(zǐ)1st earthly branch: 11 p.m.–1 a.m., midnight, 11th solar month (7th December to 5th January), year of the rat