दिवसस्य हरत्यर्कः षष्टिभागमृतौ ततः ॥ कZ_०२.२०.६५अब् ॥
divasasya haraty arkaḥ ṣaṣṭi-bhāgam ṛtau tataḥ
In each season, the sun (arka) takes away one-sixtieth part of a day (i.e., effects a seasonal shift in day-length/time).
To justify precise correction rules so state schedules (ritual dates, pay, tax deadlines, court sessions) do not drift over time.