The word hora means a vedic time unit equivalent to an hour and in all likelihood has been the root of the same word. It is derived from two words “aHO” & “ratRA” meaning “day” & “night” respectively. Thus hora also means the most primary two-fold division of time on the basis of the day & night. This takes into account not only the time frames but also the quality of time like the day is dominated or ruled by the Sun and the night by the Moon. This word also forms the first sub-division of the signs into two Hora’s ruled by the Sun & Moon. Thus, the word HORA broadly describes the quantity and quality of time.
In a week, on each of the seven days, starting from the sunrise or sunset time, there are 24 horas ruled by the seven planets. The Lord of the weekday always forms the first hora at sunrise. Depending on the ruling planet the horas are either suitable or inimical for various undertakings. This can be used to select a suitable time for an undertaking.
Hora chart shows the day and the planet ruling the hora at any given time of the day. Knowledge of the horaphala (Fruits of the Hour) gives greater insights for the native to plan their activities that is harmonised or in sync with the planetary ruler which governs a particular Hora.