alias isdate {tokenize 47 $1 | return $iif(. isin $1,0,$iif($1 > $iif($2 = 2,29,30) && . !isin $calc($2/2),0,$iif($1 >= 29 && $2 = 2 && . isin $calc($3/ $iif($right($3,2) = 0,400,4)),0,$iif($1 isnum 1-31,$iif($2 isnum 1-12,$iif($3 isnum 1-9999,1,0),0),0))))}