In Jainism, the "Parshvanath Stotra" (also called "Parshwanath Vandana" or "Parshwanath Ashtak") is a devotional hymn dedicated to Lord Parshvanath, the 23rd Tirthankara. There is no strict rule about when it must be recited, but according to Jain tradition and practice:

• Daily Practice: Devotees often recite the Parshvanath Stotra during their daily prayers, typically in the morning after completing personal hygiene and before breakfast, or in the evening during pratikraman (spiritual reflection).
• Special Occasions: It is especially recited on special days dedicated to Lord Parshvanath, such as his birth (Janma Kalyanak) or Nirvan Kalyanak, and during Parshvanath festivals or pujas.
• Personal Needs: Many Jains recite this stotra in times of distress, illness, or when seeking spiritual strength, peace, and protection, as it is believed to grant peace of mind and remove obstacles.

General Guidance: The stotra should be read with devotion, focus, and a pure mind, ideally in a clean and quiet environment. There is no restriction on the number of times or the time of day, but consistency and sincerity are valued in Jain worship.

Summary: You may read the Parshvanath Stotra at any time, but it is commonly recited during daily prayers, special occasions related to Lord Parshvanath, or whenever you seek spiritual solace.