New Zealand Geodetic Datum 1949 (NZGD49)

NZGD49 was a static horizontal datum established from astronomical observations and triangulation. LINZ records that triangulation was completed in 1942 and the astronomical observations in 1949; the initial adjustment included 284 first-order stations. The coordinates were then held fixed.

NZGD49 is a datum, not a map projection. Historic coordinates may retain network distortions, so moving them into a modern reference system requires an appropriate transformation rather than a label change.