"soon before"

[sagehen]

I have to admit that there is a nice economy to  "how soon before X  was
Y?" vs. "how much earlier was Y than X", but, in spite of that, I *think* I
would still tend to avoid it.
"Soon"  seems to me to have a kind of afterness in it, so I have no problem
with "soon after."  It would be constrained by the fixedness of  the
events.  That is, I wouldn't say, "How soon after your party was the Fourth
of July?"  but could say "How soon after the Fourth was your party?" or, of
course, ..."will your party be?"  (I realize that this is entirely
whimsical ....something to do with the Humpty Dumpty quotient.)
AM