This script checks your target coordinates every 5 minutes to see if they're in peacetime yet, and once they are announces it in alliance chat and stops. Just edit the target = line with your target's coordinates.

target = "152,605"

// Nothing to edit below here.
label start
execute "scanmap " + target + " 5"
x = GetDetailInfo(GetFieldId(target), false, 60)
if !x repeat
if x.state != 1 goto statex
echo "*** ATTENTION *** " + x.userName + " is now in peacetime!"
execute "alliancechat *** ATTENTION *** " + x.userName + " is now in peacetime!"
end

label statex
echo x.userName + " is not in peacetime yet, so we'll keep checking."
sleep 300
goto start