Stabilize reminder service specs

spec/services/reminders/set_attributes_service_spec.rb

@@ -31,6 +31,7 @@
 require "spec_helper"
 
 RSpec.describe Reminders::SetAttributesService do
+  let(:business_day_at_noon) { Time.zone.local(2025, 1, 8, 12, 0, 0) }
   let(:user) { build_stubbed(:user) }
   let(:model_instance) { Reminder.new }
   let(:remindable) { build_stubbed(:work_package) }
@@ -44,6 +45,14 @@ RSpec.describe Reminders::SetAttributesService do
                         contract_class:)
   end
 
+  before do
+    travel_to(business_day_at_noon)
+  end
+
+  after do
+    travel_back
+  end
+
   describe "building remind_at timestamp" do
     it "sets the remind_at attribute from date and time params" do
       params = {

spec/services/reminders/update_service_spec.rb

@@ -39,18 +39,24 @@ RSpec.describe Reminders::UpdateService do
   describe "remind_at changed" do
     subject { described_class.new(user:, model: model_instance).call(call_attributes) }
 
+    let(:business_day_at_noon) { Time.zone.local(2025, 1, 8, 12, 0, 0) }
     let(:model_instance) { create(:reminder, :scheduled, :with_unread_notifications, creator: user) }
     let(:user) { create(:admin) }
-    let(:remind_at) { 2.days.from_now.change(hour: 12, min: 0) }
+    let(:remind_at) { business_day_at_noon + 2.days }
     let(:call_attributes) { { remind_at_date: remind_at.to_date, remind_at_time: remind_at.strftime("%H:%M") } }
 
     before do
-      model_instance.update(job_id: 1)
+      travel_to(business_day_at_noon)
+      model_instance.update!(job_id: 1)
       allow(Reminders::ScheduleReminderJob).to receive(:schedule)
         .with(model_instance)
         .and_return(instance_double(Reminders::ScheduleReminderJob, job_id: 2))
     end
 
+    after do
+      travel_back
+    end
+
     context "with an existing unfinished scheduled job" do
       let(:job) { instance_double(GoodJob::Job, finished?: false, destroy: true) }
 
@@ -101,7 +107,7 @@ RSpec.describe Reminders::UpdateService do
     end
 
     context "with remind_at attribute in non-utc timezone" do
-      let(:call_attributes) { { remind_at: 2.days.from_now.in_time_zone("Africa/Nairobi") } }
+      let(:call_attributes) { { remind_at: remind_at.in_time_zone("Africa/Nairobi") } }
 
       it "reschedules the reminder" do
         expect { subject }.to change(model_instance, :job_id).from("1").to("2")