Answer

After sunset, if you have already completed Ayambil, the usual pachkan is:

“Chauvihar pachkan”

This means you take a vow not to consume any food or water until the next morning, as per the time and method followed in your tradition.

Explanation

In Jain practice:

• Ayambil means eating only one simple, tasteless meal during the day, following the rules of Ayambil.
• After sunset, Jains generally avoid eating and drinking.
• Chauvihar means renouncing all four types of intake:
  • Food
  • Water
  • Mukhvas / mouth-fresheners
  • Any other edible or drinkable intake

So after Ayambil is completed and sunset has passed, Chauvihar pachkan is generally appropriate.

Important Note

If you are unable to do Chauvihar due to health, medicine, age, travel, or weakness, you should ask your Guru Bhagwant, साधु-साध्वीजी, or knowledgeable Jain elder. In some situations, people may take a different pachkan according to capacity.

Takeaway

After sunset and after completing Ayambil, the ideal Jain practice is to take Chauvihar pachkan, if your health and circumstances allow it.