require 'time'
click_counts = {}
1.upto(30) { |i| click_counts[Time.parse("2006-09-#{i}")] = 400 + rand(700) }
p click_counts

{Sat Sep 23 00:00:00 EDT 2006=>803, Tue Sep 12 00:00:00 EDT 2006=>829,
Fri Sep 01 00:00:00 EDT 2006=>995, Mon Sep 25 00:00:00 EDT 2006=>587,
...

{Sat Sep 23 00:00:00 EDT 2006=>803, Tue Sep 12 00:00:00 EDT 2006=>829, Fri Sep 01 00:00:00 EDT 2006=>995, Mon Sep 25 00:00:00 EDT 2006=>587, Thu Sep 14 00:00:00 EDT 2006=>449, Sun Sep 03 00:00:00 EDT 2006=>888, Wed Sep 27 00:00:00 EDT 2006=>948, Sat Sep 16 00:00:00 EDT 2006=>592, Tue Sep 05 00:00:00 EDT 2006=>637, Fri Sep 29 00:00:00 EDT 2006=>1083, Mon Sep 18 00:00:00 EDT 2006=>933, Thu Sep 07 00:00:00 EDT 2006=>747, Wed Sep 20 00:00:00 EDT 2006=>697, Sat Sep 09 00:00:00 EDT 2006=>1002, Fri Sep 22 00:00:00 EDT 2006=>457, Mon Sep 11 00:00:00 EDT 2006=>406, Sun Sep 24 00:00:00 EDT 2006=>817, Wed Sep 13 00:00:00 EDT 2006=>924, Sat Sep 02 00:00:00 EDT 2006=>440, Tue Sep 26 00:00:00 EDT 2006=>951, Fri Sep 15 00:00:00 EDT 2006=>859, Mon Sep 04 00:00:00 EDT 2006=>431, Thu Sep 28 00:00:00 EDT 2006=>977, Sun Sep 17 00:00:00 EDT 2006=>412, Wed Sep 06 00:00:00 EDT 2006=>860, Sat Sep 30 00:00:00 EDT 2006=>415, Tue Sep 19 00:00:00 EDT 2006=>960, Fri Sep 08 00:00:00 EDT 2006=>439, Thu Sep 21 00:00:00 EDT 2006=>991, Sun Sep 10 00:00:00 EDT 2006=>1065}

low_click_days = click_counts.select {|key, value| value < 450 }

[[Thu Sep 14 00:00:00 EDT 2006, 449], [Mon Sep 11 00:00:00 EDT 2006, 406],
[Sat Sep 02 00:00:00 EDT 2006, 440], [Mon Sep 04 00:00:00 EDT 2006, 431],
...

low_click_days_hash = click_counts.inject({}) do |h, kv|
  k, v = kv
  h[k] = v if v < 450
  h
end

low_click_days_hash = Hash[*low_click_days.flatten]