date

char.awk:

BEGIN {
  FS=OFS=","
  SEPslash="/"
}
{
  for(i=1; i<=NF; i++) {
     if (split($i, a, SEPslash) != 3 || match($i, "[^0-9/]"))
        continue;
     split($i, a, "/")
     $i=a[3] sprintf("%02d",a[1]) sprintf("%02d", a[2])
  }
  print
}