If newdate works as sitecommand as you seem to have testet the configuration is correct of ioA. That leaves us with the scheduler and this is where the problem is.
Timezones is a problem
vanisher
I think it should work for you if you have it set to use local time. perhaps trigger it 1 min after full hour just in case clocks is a tick after or so. dunno how precise ioftpd scheduler is.
MonsterDK
My guess is that your danish(due to DK) so for you the following line might work. Also set it to use locatime instead of utc
Newday = 1 22 * * EXEC ..\scripts\ioA\ioA.exe NEWDATE