रात्रिभागौ द्वौ स्वप्नकाला त्रिभागः संवेशनोत्थानिकः ॥ कZ_०२.३१.०७ ॥
rātribhāgau dvau svapna-kālā tribhāgaḥ saṃveśana-utthānikaḥ
Dos divisiones de la noche son para dormir; la tercera es para acomodarse y despertarse (manejo/vigilancia nocturna).
It implies planned night supervision—checks, repositioning, readiness to respond to disturbances—rather than leaving valuable assets unattended.