Measurement of time and space as mentioned in Chapter XX of Book II in Arthashastra shall provide the chart according to which the time space, day, night, forenoon, afternoon and dawn shall be assessed. In Arthashastra this has been discussed in relation to a list which clearly marks the time period according to which the kingdom will function. Primarily based on solar timing, it had been one of the most accurate calendars of the age.
Kautilya writes 108 arigulas are equal to 1 garhapatya dhanus (i.e. a measure used by carpenters called grhapm .This measure is used in measuring roads and fort walls. The same (108 arigulas), 107 are equal to 1 paurusha, a measure used in building sacrificial altars. 6 kamsas or 192 arigulas are equal to 1 danda, used in measuring such lands as are gifted to Brahmans.
The divisions of time are referred to as truti, lava, nimesha, kashtha, kala, nalika, muhurta, paksha, ritu (season), ayana (solstice), samvatsara (year) and yuga. Measurement of time and space then makes an estimate of the daytime according to the length of the sun`s shadows. As mentioned in Arthashastra, when the length of shadow is eight paurushas (96 angulas), it is 1/18th part of the day. When it is 6 paurushas (72 angulas), it is 1/14th part of the day; when 4 paurushas, 1/8th part; when 2 paurushas, 1/6th part; when 1 paurusha, 1/4th part; when it is 8 arigulas, 1/10th part (trayodasabhagah); when 4 arigulas, 3/8th part and when no shadow is cast, it is to be considered midday. Likewise when the day declines, the same process in reverse order shall be observed.
Measurement of time and space in Arthashastra also includes the classification of months in accordance with the length of the shadows. However, there are exceptional cases, as during the month of Ashadha, no shadows are formed in the midday. In such cases the length is calculated according to the decreasing and increasing size of the shadows in the months before and after i.e. in the month of sravana and magha. Similarly this process was reiterated in case of calculating fifteen days and nights to calculate one month followed by twelve months a year. The calendar has been divided according to lunar months called Chandramasda; in which two months make one ritu which includes six sets of ritus in India. Sravana and Prokshthapa are rainy seasons; Asvayuja and Kartika make autumn; Marghshirsha and phausha make winter; magh and phalgun make dewy season; chaitra and vaishak make spring; and jyeshthamuliya and ashadha make summer.
Measurement of Time and Space, thus, remain relevant as it is vital source for calculating time.
