In Jain practice, pachkhan (pachchhkan) is always for the future, not to “change” what you have already done.

So after you have completed ekashna:

1. Same day – no new eating pachkhan

- Once you have taken pachkhan of ekashna and eaten your one meal, you should not take a new pachkhan to eat again the same day. - For the rest of that day you remain without further food (and water as per your niyam).

1. What pachkhan can you take after ekashna?

After finishing the meal you may take a simple pachkhan for the remainder of the day, for example (in your own language): - “Aaj ke bache hue samay mein main kuch bhi nahi khaunga (aur paani bhi sirf niyam ke anusaar hi loonga).” This just re‑confirms that your ekashna will be kept properly till next sunrise.

1. Pachkhan for the next day

If you wish, you can also set tomorrow’s niyam after ekashna, such as: - Navkarsi - Ekashna again - Upvas, etc. That pachkhan will then apply from the next sunrise.

1. Sect notes (brief)

- Shwetambar: Usually ekashna is in daytime before sunset; after that, only boiled water (if allowed by your niyam) and no second meal. - Digambar: Often stricter on time (before noon) and on water rules. Follow the niyam taught by your own guru / sangh.

So: after ekashna you do not take pachkhan to eat again that day; you only (a) reaffirm no more food for the day, and/or (b) take pachkhan for the next day’s aahar niyam.

You can read a simple guide on how to do ekashna here