> Obviously all has to do with what one is most likely to want
> to communicate or to leave out. We discuss recent events more
> often than remote ones, so years are elided more often than days
> -- otoh, seconds are not very useful on their own.
No. This has to do with what the speaker thinks of first. Not with what
needs to be communicated first. Speech is shaped in a field of forces
between two poles: the laziness of the speaker and that of the listener.
Also, speaking of elision here is wrong.