Where does the word ダイヤ come from that means "train schedule"?


For the longest time I've been hearing the word ダイヤ and just always assumed it
meant "Diamond", but found recently it all means "train schedule". My question
is, what word/language did this word originally come from?




Original word is from "Diagram" ダイヤグラム, which is a 外来語.




Original word is from "Diagram" ダイヤグラム, which is a 外来語.

