By-and-by and On time

By-and-by noun - Time that is to come.

On time and by-and-by are semantically related. In some cases you can use "On time" instead an adverb phrase "By-and-by".

On time adverb - At the expected time.

By-and-by and on time are semantically related. Sometimes you can replace phrase "By-and-by" with "On time", this phrases are similar.