diff --git a/bullet_train/app/models/concerns/memberships/base.rb b/bullet_train/app/models/concerns/memberships/base.rb
index 8b30ac741..33751aab8 100644
--- a/bullet_train/app/models/concerns/memberships/base.rb
+++ b/bullet_train/app/models/concerns/memberships/base.rb
@@ -32,6 +32,8 @@ module Memberships::Base
 
     after_commit :publish_changed_quantity
 
+    after_create :set_team_time_zone, if: :is_first_membership?
+
     after_validation :remove_user_profile_photo, if: :user_profile_photo_removal?
 
     scope :excluding_platform_agents, -> { where(platform_agent_of: nil) }
@@ -157,5 +159,13 @@ def publish_changed_quantity
     ActiveSupport::Notifications.instrument("memberships.quantity-changed", {team:})
   end
 
+  def set_team_time_zone
+    team.set_time_zone_from_user(user)
+  end
+
+  def is_first_membership?
+    team.memberships.count == 1 && team.memberships.first.id == id
+  end
+
   ActiveSupport.run_load_hooks :bullet_train_memberships_base, self
 end
diff --git a/bullet_train/app/models/concerns/teams/base.rb b/bullet_train/app/models/concerns/teams/base.rb
index dcd077a71..fa4410a6a 100644
--- a/bullet_train/app/models/concerns/teams/base.rb
+++ b/bullet_train/app/models/concerns/teams/base.rb
@@ -30,6 +30,11 @@ def initialize(attributes = nil)
     self.time_zone = "UTC" if time_zone.blank?
   end
 
+  def set_time_zone_from_user(user)
+    self.time_zone = user.time_zone if user.time_zone.present?
+    save
+  end
+
   def platform_agent_access_tokens
     Platform::AccessToken.joins(:application).where(resource_owner_id: users.where.not(platform_agent_of_id: nil), application: {team: nil})
   end
diff --git a/bullet_train/test/models/team_test.rb b/bullet_train/test/models/team_test.rb
index 3058c3721..d8ace514c 100644
--- a/bullet_train/test/models/team_test.rb
+++ b/bullet_train/test/models/team_test.rb
@@ -6,6 +6,14 @@ class TeamTest < ActiveSupport::TestCase
     assert_equal "UTC", team.time_zone
   end
 
+  test "explicitly set time_zone is not clobbered by first user" do
+    team = Team.create!(name: "new test team", time_zone: "Eastern Time (US & Canada)")
+    user = User.create!(email: "test@test.com", password: "password", password_confirmation: "password", time_zone: "Central Time (US & Canada)")
+    Membership.create!(team: team, user: user)
+    team.reload
+    assert_equal "Eastern Time (US & Canada)", team.time_zone
+  end
+
   test "a new team gets the time_zone of the first user when they join" do
     team = Team.create!(name: "new test team")
     user = User.create!(email: "test@test.com", password: "password", password_confirmation: "password", time_zone: "Central Time (US & Canada)")
@@ -13,4 +21,26 @@ class TeamTest < ActiveSupport::TestCase
     team.reload
     assert_equal "Central Time (US & Canada)", team.time_zone
   end
+
+  test "default UTC time_zone is not clobbered if first user doesn't have a time zone set" do
+    team = Team.create!(name: "new test team")
+    user = User.create!(email: "test@test.com", password: "password", password_confirmation: "password", time_zone: nil)
+    Membership.create!(team: team, user: user)
+    team.reload
+    assert_equal "UTC", team.time_zone
+  end
+
+  test "default UTC time_zone is overwritten once the first user sets a time zone" do
+    team = Team.create!(name: "new test team")
+    user = User.create!(email: "test@test.com", password: "password", password_confirmation: "password", time_zone: nil)
+    Membership.create!(team: team, user: user)
+    team.reload
+    assert_equal "UTC", team.time_zone
+
+    user.time_zone = "Central Time (US & Canada)"
+    user.save
+
+    team.reload
+    assert_equal "Central Time (US & Canada)", team.time_zone
+  end
 end