Answer

In Tivihar Upvas, water may be taken only before sunset.

So the correct time is not a fixed 6:00 or 6:45 for everyone. It depends on the actual sunset time at your location on that day.

If sunset is around 6:45 pm, then traditionally you should finish drinking water before 6:45 pm, preferably a few minutes earlier.

Explanation

In Jain practice:

• Chauvihar means no food and no water after sunset.
• Tivihar usually means no food, but water is allowed during the permitted time, generally until sunset.

For safety and proper observance, many people stop water 5–10 minutes before sunset, rather than exactly at sunset.

Takeaway

If today’s sunset in your place is approximately 6:45 pm, drink water before that, ideally by around 6:35–6:40 pm. If your local Jain tradition or guru has given a stricter time, follow that.