> I asked how you would express a time 10s before t=0 and you said t=-10s.

OK let's start from the beginning....how do you express 10s before t=0?

> I asked how you would express a time 10s after t=0 and you said t=+10s.

OK let's start from the beginning...how do you express 10s after t=0?

> You are now claiming that the -/+ has nothing to do with before/after t=0,

I am claiming that -10s before t=0 and +10s after t=0 cannot be two
simultaneous events. I am claiming that two coordinates (-10m, -10s)
and (+10m, +10s) can be two simultaneous events. Notice I don't use
before or after a certain t=0. You completely miss interpreted the
discussion in this thread.