शिशिराद्युत्तरायणम् ॥ कZ_०२.२०.६१ ॥
śiśirādy uttarāyaṇam
उत्तरायण शिशिर (शीत ऋतु) से आरम्भ होता है।
It divides the year into predictable half-year blocks used for planning campaigns, audits, and seasonal resource management.