In Jainism, "pachkan" (also spelled pachkhan) is a formal vow or resolve taken to define and limit one’s intake or actions, often recited before or during fasting (upvas). "Sajala upvas" refers to a fast in which you abstain from food but may consume water.

Traditionally, the pachkan for sajala upvas should be taken in the morning, ideally before or around sunrise, and definitely before you begin your fast. The exact permissible time can vary based on local tradition and the specific sect (Shwetambar or Digambar) you follow.

Generally, taking pachkan at 11:00 AM is considered late, as Jain teachings emphasize taking religious vows and starting fasts early in the morning, aligning with the concept of ahar-daan (food intake) and the purity of the morning hours. However, if there are exceptional circumstances, it is best to consult with a Jain monk, nun, or a respected elder in your community for guidance according to your tradition.

In summary: Ideally, pachkan for sajala upvas should be taken in the morning, before or shortly after sunrise. Taking it at 11:00 AM is generally not recommended, but please confirm with a knowledgeable person in your Jain community for exceptions.