diff --git a/CHANGES.md b/CHANGES.md
index c980ed0..c06b0e5 100755
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -3,6 +3,7 @@
 - 1.4.0 (unreleased)
   - track CPU, memory, storage: https://github.com/igorkasyanchuk/rails_performance/pull/111
   - use UTC time: https://github.com/igorkasyanchuk/rails_performance/pull/114
+  - custom expiration time for system monitoring report: https://github.com/igorkasyanchuk/rails_performance/pull/115/files
 
 - 1.3.3
   - little improvements and bug fixes
diff --git a/Gemfile.lock b/Gemfile.lock
index aac30fe..59a0448 100755
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    rails_performance (1.4.0.alpha4)
+    rails_performance (1.4.0.alpha5)
       browser
       railties
       redis
diff --git a/README.md b/README.md
index 78271a8..c409e62 100755
--- a/README.md
+++ b/README.md
@@ -117,6 +117,10 @@ RailsPerformance.setup do |config|
 
   # To monitor custom events with `RailsPerformance.measure` block
   # config.include_custom_events = true
+
+  # To monitor system resources (CPU, memory, disk)
+  # to enabled add required gems (see README)
+  # config.system_monitor_duration = 24.hours
 end if defined?(RailsPerformance)
 ```
 
diff --git a/app/controllers/rails_performance/rails_performance_controller.rb b/app/controllers/rails_performance/rails_performance_controller.rb
index 5a5c7ad..6fe54e7 100755
--- a/app/controllers/rails_performance/rails_performance_controller.rb
+++ b/app/controllers/rails_performance/rails_performance_controller.rb
@@ -15,7 +15,7 @@ def index
       end
 
       def resources
-        @datasource = RailsPerformance::DataSource.new(**prepare_query(params), type: :resources)
+        @datasource = RailsPerformance::DataSource.new(**prepare_query(params), type: :resources, days: RailsPerformance::Utils.days(RailsPerformance.system_monitor_duration))
         db = @datasource.db
 
         @resources_report = RailsPerformance::Reports::ResourcesReport.new(db)
diff --git a/lib/generators/rails_performance/install/templates/initializer.rb b/lib/generators/rails_performance/install/templates/initializer.rb
index 20a5b05..3430230 100644
--- a/lib/generators/rails_performance/install/templates/initializer.rb
+++ b/lib/generators/rails_performance/install/templates/initializer.rb
@@ -52,5 +52,9 @@
     config.skipable_rake_tasks = ["webpacker:compile"]
     config.include_rake_tasks = false
     config.include_custom_events = true
+
+    # If enabled, the system monitor will be displayed on the dashboard
+    # to enabled add required gems (see README)
+    # config.system_monitor_duration = 24.hours
   end
 end
diff --git a/lib/rails_performance.rb b/lib/rails_performance.rb
index fd51543..9bea4cf 100755
--- a/lib/rails_performance.rb
+++ b/lib/rails_performance.rb
@@ -119,6 +119,14 @@ def self.ignored_paths=(paths)
   mattr_accessor :ignore_trace_headers
   @@ignore_trace_headers = ["datetimei"]
 
+  # System monitor duration (expiration time)
+  mattr_accessor :system_monitor_duration
+  @@system_monitor_duration = 24.hours
+
+  # -- internal usage --
+  #
+  #
+  # to store the resource monitor instance
   mattr_accessor :_resource_monitor
   @@_resource_monitor = nil
 
diff --git a/lib/rails_performance/data_source.rb b/lib/rails_performance/data_source.rb
index f02e638..61dea49 100755
--- a/lib/rails_performance/data_source.rb
+++ b/lib/rails_performance/data_source.rb
@@ -10,19 +10,20 @@ class DataSource
       resources: RailsPerformance::Models::ResourceRecord
     }
 
-    attr_reader :q, :klass, :type
+    attr_reader :q, :klass, :type, :days
 
-    def initialize(type:, q: {})
+    def initialize(type:, q: {}, days: RailsPerformance::Utils.days(RailsPerformance.duration))
       @type = type
       @klass = KLASSES[type]
       q[:on] ||= Date.today
       @q = q
+      @days = days
     end
 
     def db
       result = RailsPerformance::Models::Collection.new
       now = RailsPerformance::Utils.time
-      (0..(RailsPerformance::Utils.days)).to_a.reverse_each do |e|
+      (0..days).to_a.reverse_each do |e|
         RailsPerformance::DataSource.new(q: q.merge({on: (now - e.days).to_date}), type: type).add_to(result)
       end
       result
diff --git a/lib/rails_performance/models/resource_record.rb b/lib/rails_performance/models/resource_record.rb
index adf024c..08c07b8 100644
--- a/lib/rails_performance/models/resource_record.rb
+++ b/lib/rails_performance/models/resource_record.rb
@@ -40,7 +40,8 @@ def record_hash
 
       def save
         key = "resource|server|#{server}|context|#{context}|role|#{role}|datetime|#{datetime}|datetimei|#{datetimei}|END|#{RailsPerformance::SCHEMA}"
-        Utils.save_to_redis(key, json)
+        # with longer expiration time
+        Utils.save_to_redis(key, json, RailsPerformance.system_monitor_duration.to_i)
       end
     end
   end
diff --git a/lib/rails_performance/reports/base_report.rb b/lib/rails_performance/reports/base_report.rb
index 991bee9..ee80791 100755
--- a/lib/rails_performance/reports/base_report.rb
+++ b/lib/rails_performance/reports/base_report.rb
@@ -63,14 +63,14 @@ def calculate_data
       #   1732125550000 => 0,
       #   ....
       # }
-      def nil_data
+      def nil_data(duration = RailsPerformance.duration)
         @nil_data ||= begin
           result = {}
           now = RailsPerformance::Utils.time
           now = now.change(sec: 0, usec: 0)
           stop = now # Time.at(60 * (now.to_i / 60))
           offset = 0 # RailsPerformance::Reports::BaseReport.time_in_app_time_zone(now).utc_offset
-          current = stop - RailsPerformance.duration
+          current = stop - duration
 
           while current <= stop
             current.strftime(RailsPerformance::FORMAT)
@@ -86,8 +86,8 @@ def nil_data
       #   1732125540000 => 1,
       #   1732125550000 => 0,
       # }
-      def nullify_data(input)
-        nil_data.merge(input).sort
+      def nullify_data(input, duration = RailsPerformance.duration)
+        nil_data(duration).merge(input).sort
       end
     end
   end
diff --git a/lib/rails_performance/reports/resources_report.rb b/lib/rails_performance/reports/resources_report.rb
index ef9a9e0..f93a62c 100644
--- a/lib/rails_performance/reports/resources_report.rb
+++ b/lib/rails_performance/reports/resources_report.rb
@@ -5,13 +5,13 @@ def data
         @data ||= db.data
           .collect { |e| e.record_hash }
           .group_by { |e| e[:server] + "///" + e[:context] + "///" + e[:role] }
-          .transform_values { |v| v.sort { |a, b| b[sort] <=> a[sort] } }
+          # .transform_values { |v| v.sort { |a, b| b[sort] <=> a[sort] } }
           .transform_values { |v| v.map { |e| e.merge({datetimei: e[:datetimei].to_i}) } }
       end
 
       def cpu
         @cpu ||= data.transform_values do |v|
-          nullify_data(v.each_with_object({}) do |e, res|
+          prepare_report(v.each_with_object({}) do |e, res|
             res[e[:datetimei] * 1000] = e[:cpu]["one_min"].to_f.round(2)
           end)
         end
@@ -19,7 +19,7 @@ def cpu
 
       def memory
         @memory ||= data.transform_values do |v|
-          nullify_data(v.each_with_object({}) do |e, res|
+          prepare_report(v.each_with_object({}) do |e, res|
             res[e[:datetimei] * 1000] = e[:memory].to_f.round(2)
           end)
         end
@@ -27,11 +27,17 @@ def memory
 
       def disk
         @disk ||= data.transform_values do |v|
-          nullify_data(v.each_with_object({}) do |e, res|
+          prepare_report(v.each_with_object({}) do |e, res|
             res[e[:datetimei] * 1000] = e[:disk]["available"].to_f.round(2)
           end)
         end
       end
+
+      private
+
+      def prepare_report(input)
+        nullify_data(input, RailsPerformance.system_monitor_duration)
+      end
     end
   end
 end
diff --git a/lib/rails_performance/utils.rb b/lib/rails_performance/utils.rb
index 40a8597..2e4ae9c 100755
--- a/lib/rails_performance/utils.rb
+++ b/lib/rails_performance/utils.rb
@@ -40,8 +40,8 @@ def self.save_to_redis(key, value, expire = RailsPerformance.duration.to_i)
       RailsPerformance.redis.set(key, value.to_json, ex: expire.to_i)
     end
 
-    def self.days
-      (RailsPerformance.duration / 1.day) + 1
+    def self.days(duration = RailsPerformance.duration)
+      (duration / 1.day) + 1
     end
 
     def self.median(array)
diff --git a/lib/rails_performance/version.rb b/lib/rails_performance/version.rb
index e0832a8..e0b5f01 100755
--- a/lib/rails_performance/version.rb
+++ b/lib/rails_performance/version.rb
@@ -1,4 +1,4 @@
 module RailsPerformance
-  VERSION = "1.4.0.alpha4"
+  VERSION = "1.4.0.alpha5"
   SCHEMA = "1.0.2"
 end
diff --git a/test/dummy/config/initializers/rails_performance.rb b/test/dummy/config/initializers/rails_performance.rb
index a3566ae..f65521d 100755
--- a/test/dummy/config/initializers/rails_performance.rb
+++ b/test/dummy/config/initializers/rails_performance.rb
@@ -35,5 +35,9 @@
 
     config.include_rake_tasks = true
     config.include_custom_events = true
+
+    # If enabled, the system monitor will be displayed on the dashboard
+    # to enabled add required gems (see README)
+    config.system_monitor_duration = 24.hours
   end
 end