Your date chart must have to be like an arrow. At the begining, put the farest date with some globals informations. Then, do an increasing chart, where you have to be proportional with the times and the length. At the end you will have the earliest date (like nowadays).
The New General Catalogue of Nebulae and Clusters of Stars (abbreviated as NGC) is a catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888.
