A small birth time confusion usually does NOT make a major difference in your astrology reading unless your lagan/ascendant is changing in your birth chart. A lagan is for approximately 2 hours. You should check with your astrologer to see if your lagan changes during the time difference. If it changes, then the second thing you can do is go in for birth time rectification. In birth time rectification, an astrologer matches your past life events to find your accurate birth chart.