Գերդաստան [kertasdan], though is widely used in armenian, doesn't sound armenian at all (too eastern). Տոհմ [tohm] is the proper armenian word for it. though, this doesn't sound armenian either (too western).
during Վաղարշապատ [Vagharshabad], armenians probably didn't even know about arab's existance.
more about կերտ [gerd] (կերտել, քերթել),
http://hyeforum.com/index.php?showtopic=9604
isn't time in arabic "s'haat"?