@osiris4isis, My TomTom maps have a specific school zone file, wheras the Here maps don't. I generally use TomTom maps and they definitely show school zone signs when active but not when inactive. I haven't tried Here maps yet but can do that shortly and report back. I'll see if I can get some screenshots as well.

@nommad, I'm not sure what warning_time_interval_adjust does, but my guess is that it introduces a fudge factor of 2 minutes to the times to cover any overlap where any time controlled warning signs outside the school itself are a bit out time wise.

Cheers, Ian