In classical Chinese cosmology
日月 are the two great heavenly bodies and stand for time itself. The character
明 (míng, 'bright') is famously composed of
日 +
月 — sun next to moon — and the Ming dynasty (
明朝, 1368–1644) is named accordingly. Common four-character chunks:
日月如梭 (rìyuè rú suō, 'days and months are like a weaver's shuttle' — time flies);
日月同辉 (rìyuè tóng huī, 'shining as bright as sun and moon' — eternal glory).
