The table below shows dates written with traditional numerals, but use of Arabic numerals (), which means "the month beginning".
The last day of the month was called tsugomori, which means "Moon hidden".
The names of the days come from the five visible planets, which in turn are named after the five Chinese elements (metal, wood, water, fire, earth), and from the moon and sun (yin and yang).
On the origin of the names of the days of the week, also see East Asian Seven Luminaries. These holidays have no religious meaning (except those who believe in Christianity or Judaism).
character, which normally means "absent" or "there is not", was here probably originally used as ateji, that is used only for the sound "na".