3. From the autumnal equinox, daytime further decreases for 3 months
        to the winter solstice (the shortest day–12 muhurtas–9 hrs 36
    4. From the winter solstice, daytime increases for 3 months to the vernal
III. Measuring Time
During the day, time was measured by a sundial with a gnomon (central rod
casting the shadow) of length 12 angulas (9 in.). No shadow indicated noon
lengths of the shadow of 27 in. 9 in. 3 in. before and after mid-day, divided
the day into eight parts.
    In the month of Asadha, the gnomon does not cast a shadow at mid-day.
From then on, the shadow at mid-day increases by 2 angulas (1 1⁄2 in) a
month during the six monthly period Sravana to Pausha. From Magha to
Ashada, the mid-day shadow decreases by 2 angulas each month.
IV. Calendar
     15 days (and nights) = Sukla fortnight (waning moon) Bakula fortnight
     (waxing moon)
     2 fortnights                              = 1 month
     2 months                                  = 1 season
     3 seasons                                 = 1 ayana
     2 ayanas                                  = 1 year
     years                                     = 1 yuga
V. Note on Seasons
    A. Uttarayana
        l. Sisira (frosty)—Magha (Jan/Feb) and Phalguna (Feb/Mar)
        2. Vasantha (spring)—Chaitra (Mar/Apr) and Vaishaka (Apr/May)
        3. Grishma (summer)—Jyeshtamulya (May/Jun) and Ashada
    B. Dakshinayana
        l. Varsha (rainy)—Sravana (July/Aug) and Praushtapada (Aug/Sep)
        2. Sharat (autumn)—Asvayzlja (Sep/Oct) and Kartika (Oct/Nov)
        3. Hemanta (winter)–Marghasirsha (Nov/Dec) and Pausha