Changed validation error message on wrong milestone dates

app/models/milestone.rb

@@ -256,7 +256,7 @@ class Milestone < ActiveRecord::Base
 
   def start_date_should_be_less_than_due_date
     if due_date <= start_date
-      errors.add(:start_date, "Can't be greater than due date")
+      errors.add(:due_date, "must be greater than start date")
     end
   end
 

changelogs/unreleased/38393-Milestone-duration-error-message-is-not-accurate-enough.yml

@@ -0,0 +1,5 @@
+---
+title: Changed validation error message on wrong milestone dates
+merge_request:
+author: Xurxo Méndez Pérez
+type: fixed

spec/models/milestone_spec.rb

@@ -11,7 +11,7 @@ describe Milestone do
         milestone = build(:milestone, start_date: Date.tomorrow, due_date: Date.yesterday)
 
         expect(milestone).not_to be_valid
-        expect(milestone.errors[:start_date]).to include("Can't be greater than due date")
+        expect(milestone.errors[:due_date]).to include("must be greater than start date")
       end
     end
   end