A recorded birth time just after 9 a.m. may cross a two-hour boundary after a local solar-time adjustment. If two Zi Wei Dou Shu apps disagree, do not pick the chart with the nicer story. Compare the input and calculation rules first.
Make a comparison table
Record the original time, birthplace, time zone, daylight-saving rule and solar-time setting. List which Life, Body, Career and Wealth positions change between the two charts. Use several dated, independently recorded life events rather than a single promotion to assess fit.
Keep uncertainty visible
If the natal chart remains uncertain, later timing layers inherit that uncertainty. Check calendar and star-placement settings when software differs even far from a time boundary. Avoid exact date claims until the input is established.