luty81

{
  date = $1
  hour = substr($2,1,2)
  group[date, hour]++
}END{
  print "Date" "\t\t" "Hour" "\t" "Total"
  print "====" "\t\t" "====" "\t" "======"
  for (item in group) print substr(item, 1, 10) "\t" substr(item, 11, 3) "\t", group[item]
}