This was very accurate and precise and, in places where there were exceptions, allowed for him to predict where new elements would be placed and their relative atomic mass, to a great degree of accuracy (1 ene 1869 año – 23 h 59 m, 31 dic 1869 año)
Añadido al timeline:
fecha:
1 ene 1869 año
23 h 59 m, 31 dic 1869 año
~ 12 months