Fill in a birth above.
Differences
Usually neither of you is wrong. A chart rests on four conventions — the ayanamsa, which node, which house system, and the birth time itself — and each has more than one defensible choice. Two people who choose differently get different answers from identical arithmetic. This page computes, for your birth, exactly how much each choice moves, and whether your chart is close enough to an edge for it to matter at all.
Fill in a birth above.