Answer

Yes, in general, if you have followed all the rules of upwas since morning, you may take the upwas pachchakkhān at 3 PM.

The upwas is considered to continue until the proper time of pāraṇu / pārṇā, usually after sunrise the next day, according to your tradition and local practice.

Important Point

In Jain practice, the exact validity of pachchakkhān and pāraṇu timing can depend on:

• Your Jain tradition: Śvetāmbara, Digambara, Sthānakvāsī, Terāpanth, etc.
• Your local saṅgh practice
• The specific type of upwas you are observing
• Guidance from your Guru, Maharaj Saheb, Sādhvīji, or knowledgeable elder

Takeaway

If you have maintained the fast properly from morning and take pachchakkhān at 3 PM with correct intention, the upwas generally continues until the next day’s pāraṇu after sunrise. For exact confirmation, follow your Guru or local saṅgh’s maryādā.