diff --git a/app/models/balance/chart_series_builder.rb b/app/models/balance/chart_series_builder.rb
index 034f54c67..c8c733579 100644
--- a/app/models/balance/chart_series_builder.rb
+++ b/app/models/balance/chart_series_builder.rb
@@ -1,5 +1,5 @@
 class Balance::ChartSeriesBuilder
-  def initialize(account_ids:, currency:, period: Period.last_30_days, interval: "1 day", favorable_direction: "up")
+  def initialize(account_ids:, currency:, period: Period.last_30_days, interval: nil, favorable_direction: "up")
     @account_ids = account_ids
     @currency = currency
     @period = period
diff --git a/app/models/period.rb b/app/models/period.rb
index 4188478f2..fd1de6d1c 100644
--- a/app/models/period.rb
+++ b/app/models/period.rb
@@ -165,7 +165,9 @@ class Period
   end
 
   def interval
-    if days > 366
+    if days > 1825 # 5 years
+      "1 month"
+    elsif days > 366
       "1 week"
     else
       "1 day"