Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
तदेव शैशिरं नाम वर्षं तत्परिकीर्तितम् नारदस्य च कौमारं तदेव च सुखोदयम् //
tadeva śaiśiraṃ nāma varṣaṃ tatparikīrtitam nāradasya ca kaumāraṃ tadeva ca sukhodayam //
That very period is proclaimed as the season called Śaiśira; and for Nārada it is likewise said to be the youthful (Kaumāra) phase—indeed, the same is also termed Sukhodaya (the rise of happiness/prosperity).
It does not describe Pralaya directly; it classifies a time/seasonal period by traditional names, reflecting the Purana’s broader cosmological ordering of time.
Indirectly: by naming and distinguishing time-cycles, it supports dharmic scheduling—choosing appropriate seasons/periods for rites, governance, and household observances as guided elsewhere in the Matsya Purana.
No explicit Vāstu rule is stated, but such seasonal nomenclature commonly underpins ritual timing (kāla-śuddhi) used when selecting auspicious periods for consecrations, installations, and major ceremonies.