[time-nuts] LadyHeather Cabledelay - positive or negative ?

[cfo]

Hi T-Nuts

I have a question about the Cabledelay in LH

I have a tbolt in my home (approx 25m cable , and 100nS delay)  and one 
in my summerhouse (approx 15m cable , 66nS delay).

I just discovered that i have specified a negative cabledelay of -66nS in 
my summerhouse , and i think it's wrong.

Shouldn't cabledelay always be positive ?

TIA
CFO