diff --git a/spec/models/chargeback_vm/ongoing_time_period_spec.rb b/spec/models/chargeback_vm/ongoing_time_period_spec.rb
new file mode 100644
index 00000000000..ed063e31d30
--- /dev/null
+++ b/spec/models/chargeback_vm/ongoing_time_period_spec.rb
@@ -0,0 +1,96 @@
+describe ChargebackVm do
+  let(:admin) { FactoryGirl.create(:user_admin) }
+  let(:start_of_all_intervals) { Time.parse('2007-01-01 00:00:00Z').utc } # 0hours, Monday, 1st of month
+  let(:consumed_hours) { 17 }
+  let(:midle_of_the_first_day) { start_of_all_intervals + consumed_hours.hours } # it is a Monday
+  let(:ts) { midle_of_the_first_day.in_time_zone(Metric::Helper.get_time_zone(opt[:ext_options])) }
+  let(:report_run_time) { midle_of_the_first_day }
+
+  let(:opt) do
+    {:interval_size       => 1,
+     :end_interval_offset => 0,
+     :tag                 => '/managed/environment/prod',
+     :ext_options         => {:tz => 'UTC'},
+     :userid              => admin.userid}
+  end
+  let(:tag) { Tag.find_by_name('/managed/environment/prod') }
+  let(:vm) do
+    ems = FactoryGirl.create(:ems_vmware)
+    vm = FactoryGirl.create(:vm_vmware, :name => 'test_vm', :evm_owner => admin, :ems_ref => 'ems_ref')
+    vm.tag_with(tag.name, :ns => '*')
+    host = FactoryGirl.create(:host, :hardware => FactoryGirl.create(:hardware,
+                                                                     :memory_mb => 8124, :cpu_total_cores => 1,
+                                                                     :cpu_speed => 9576), :vms => [vm])
+    ems_cluster = FactoryGirl.create(:ems_cluster, :ext_management_system => ems)
+    ems_cluster.hosts << host
+    storage = FactoryGirl.create(:storage_target_vmware)
+
+    Range.new(start_of_all_intervals, midle_of_the_first_day, true).step_value(1.hour).each do |time|
+      vm.metric_rollups << FactoryGirl.create(:metric_rollup_vm_hr,
+                                              :derived_vm_numvcpus       => number_of_cpus,
+                                              :cpu_usagemhz_rate_average => cpu_usagemhz,
+                                              :timestamp                 => time,
+                                              :tag_names                 => 'environment/prod',
+                                              :parent_host_id            => host.id,
+                                              :parent_ems_cluster_id     => ems_cluster.id,
+                                              :parent_ems_id             => ems.id,
+                                              :parent_storage_id         => storage.id,
+                                              :resource_name             => vm.name,
+                                             )
+    end
+    vm
+  end
+  let(:hourly_rate)               { 0.01 }
+  let(:count_hourly_rate)         { 1.2 }
+  let(:hourly_variable_tier_rate)       { {:variable_rate => hourly_rate.to_s} }
+  let(:count_hourly_variable_tier_rate) { {:variable_rate => count_hourly_rate.to_s} }
+  let(:detail_params) do
+    {
+      :chargeback_rate_detail_cpu_used      => {:tiers => [hourly_variable_tier_rate]},
+      :chargeback_rate_detail_cpu_allocated => {:tiers => [count_hourly_variable_tier_rate]},
+    }
+  end
+
+  let!(:chargeback_rate) do
+    cat = FactoryGirl.create(:classification, :description => 'Environment', :name => 'environment',
+                             :single_value => true, :show => true)
+    c = FactoryGirl.create(:classification, :name => 'prod', :description => 'Production', :parent_id => cat.id)
+    chargeback_rate = FactoryGirl.create(:chargeback_rate, :detail_params => detail_params)
+    temp = { :cb_rate => chargeback_rate, :tag => [c, 'vm'] }
+    ChargebackRate.set_assignments(:compute, [temp])
+  end
+
+  before do
+    MiqRegion.seed
+    ChargebackRate.seed
+    EvmSpecHelper.create_guid_miq_server_zone
+    Timecop.travel(report_run_time)
+    vm
+  end
+
+  after do
+    Timecop.return
+  end
+
+  let(:daily_cb)   { ChargebackVm.build_results_for_report_ChargebackVm(opt.merge(:interval => 'daily')).first.first }
+  let(:weekly_cb)  { ChargebackVm.build_results_for_report_ChargebackVm(opt.merge(:interval => 'weekly')).first.first }
+  let(:monthly_cb) { ChargebackVm.build_results_for_report_ChargebackVm(opt.merge(:interval => 'monthly')).first.first }
+
+  let(:number_of_cpus) { 1 }
+  let(:cpu_allocated_cost) { number_of_cpus * consumed_hours * count_hourly_rate }
+  let(:cpu_usagemhz) { 50 }
+  let(:cpu_usage_cost) { cpu_usagemhz * consumed_hours * hourly_rate }
+
+  it 'should calculate the same -- no matter the time range (daily/weekly/monthly)' do
+    [daily_cb, weekly_cb, monthly_cb].each do |cb|
+      expect(cb.start_date).to eq(report_run_time.beginning_of_month)
+      expect(cb.fixed_compute_metric).to eq(consumed_hours)
+      expect(cb.cpu_allocated_metric).to eq(number_of_cpus)
+      expect(cb.cpu_allocated_cost).to eq(cpu_allocated_cost)
+      expect(cb.cpu_used_metric).to eq(cpu_usagemhz)
+      expect(cb.cpu_used_cost).to eq(cpu_usage_cost)
+      expect(cb.total_cost).to eq(cpu_allocated_cost + cpu_usage_cost)
+      expect(cb.total_cost).to eq(28.9) # hardcoded value here keeps us honest
+    end
+  end
+end