diff --git a/ansible/playbooks/bootstrap.yaml b/ansible/playbooks/bootstrap.yaml
index 84d7611..8d80353 100644
--- a/ansible/playbooks/bootstrap.yaml
+++ b/ansible/playbooks/bootstrap.yaml
@@ -5,6 +5,8 @@
   roles:
     - role: base
       tags: [base]
+    - role: railiance_clock
+      tags: [clock]
     - role: sops_agent
       tags: [sops]
     - role: custodian_agent   # injects ~/.ssh/id_custodian_agent.pub into authorized_keys
diff --git a/ansible/playbooks/host-time.yaml b/ansible/playbooks/host-time.yaml
new file mode 100644
index 0000000..5cb5e78
--- /dev/null
+++ b/ansible/playbooks/host-time.yaml
@@ -0,0 +1,6 @@
+---
+- name: Converge only explicitly admitted host time infrastructure
+  hosts: all
+  become: true
+  roles:
+    - role: railiance_clock
diff --git a/ansible/roles/railiance_clock/defaults/main.yaml b/ansible/roles/railiance_clock/defaults/main.yaml
new file mode 100644
index 0000000..5f0121b
--- /dev/null
+++ b/ansible/roles/railiance_clock/defaults/main.yaml
@@ -0,0 +1,18 @@
+---
+# Both baseline convergence and authority activation are explicit inventory opt-ins.
+railiance_clock_enabled: false
+railiance_clock_manage_timesyncd: false
+railiance_clock_authority_enabled: false
+railiance_clock_upstreams: [ntp.ubuntu.com]
+railiance_clock_policy_id: railiance01-online-v1
+railiance_clock_install_root: /opt/railiance-clock
+railiance_clock_health_root: /run/railiance-clock
+railiance_clock_state_root: /var/lib/railiance-clock
+railiance_clock_wheelhouse: ""
+railiance_clock_wheel_sha256: ""
+railiance_clock_private_key_source: ""
+railiance_clock_kid: ""
+railiance_clock_admission_ref: ""
+railiance_clock_max_error_ns: 500000000
+railiance_clock_measurement_margin_ns: 10000000
+railiance_clock_host_drift_ppm: 1000
diff --git a/ansible/roles/railiance_clock/handlers/main.yaml b/ansible/roles/railiance_clock/handlers/main.yaml
new file mode 100644
index 0000000..fd992aa
--- /dev/null
+++ b/ansible/roles/railiance_clock/handlers/main.yaml
@@ -0,0 +1,13 @@
+---
+- name: Restart reviewed timesyncd
+  ansible.builtin.systemd:
+    name: systemd-timesyncd
+    state: restarted
+- name: Reload clock service units
+  ansible.builtin.systemd:
+    daemon_reload: true
+- name: Restart admitted clock authority
+  ansible.builtin.systemd:
+    name: railiance-clock.service
+    state: restarted
+    daemon_reload: true
diff --git a/ansible/roles/railiance_clock/tasks/authority.yaml b/ansible/roles/railiance_clock/tasks/authority.yaml
new file mode 100644
index 0000000..912bc60
--- /dev/null
+++ b/ansible/roles/railiance_clock/tasks/authority.yaml
@@ -0,0 +1,128 @@
+---
+- name: Require versioned artifact and admitted signing-key delivery
+  ansible.builtin.assert:
+    that:
+      - railiance_clock_wheelhouse | length > 0
+      - railiance_clock_wheel_sha256 is match('^[0-9a-f]{64}$')
+      - railiance_clock_private_key_source | length > 0
+      - railiance_clock_kid | length > 0
+- name: Create unprivileged authority account
+  ansible.builtin.user:
+    name: railiance-clock
+    system: true
+    shell: /usr/sbin/nologin
+    create_home: false
+- name: Create root-owned install tree
+  ansible.builtin.file:
+    path: "{{ railiance_clock_install_root }}"
+    state: directory
+    owner: root
+    group: root
+    mode: '0755'
+- name: Create private signing-key directory
+  ansible.builtin.file:
+    path: "{{ railiance_clock_state_root }}"
+    state: directory
+    owner: railiance-clock
+    group: railiance-clock
+    mode: '0700'
+- name: Create public health runtime directory
+  ansible.builtin.file:
+    path: "{{ railiance_clock_health_root }}"
+    state: directory
+    owner: root
+    group: root
+    mode: '0755'
+- name: Persist runtime directory creation across boot
+  ansible.builtin.copy:
+    dest: /etc/tmpfiles.d/railiance-clock.conf
+    content: "d {{ railiance_clock_health_root }} 0755 root root -\n"
+    owner: root
+    group: root
+    mode: '0644'
+- name: Verify selected wheel checksum on controller
+  ansible.builtin.stat:
+    path: "{{ railiance_clock_wheelhouse }}/railiance_clock-0.1.0-py3-none-any.whl"
+    checksum_algorithm: sha256
+  delegate_to: localhost
+  become: false
+  register: clock_wheel
+- name: Refuse artifact drift
+  ansible.builtin.assert:
+    that: clock_wheel.stat.checksum == railiance_clock_wheel_sha256
+- name: Copy offline wheelhouse with locked dependencies
+  ansible.builtin.copy:
+    src: "{{ railiance_clock_wheelhouse }}/"
+    dest: "{{ railiance_clock_install_root }}/wheels/"
+    owner: root
+    group: root
+    mode: '0644'
+  register: clock_artifact_copy
+- name: Install isolated authority package without network package lookup
+  ansible.builtin.pip:
+    name: railiance-clock==0.1.0
+    state: "{{ 'forcereinstall' if clock_artifact_copy.changed else 'present' }}"
+    virtualenv: "{{ railiance_clock_install_root }}/venv"
+    virtualenv_command: python3 -m venv
+    extra_args: "--no-index --find-links={{ railiance_clock_install_root }}/wheels"
+  notify: Restart admitted clock authority
+- name: Deliver admitted signing key without logging values
+  ansible.builtin.copy:
+    src: "{{ railiance_clock_private_key_source }}"
+    dest: "{{ railiance_clock_state_root }}/signing.pem"
+    owner: railiance-clock
+    group: railiance-clock
+    mode: '0600'
+  no_log: true
+  diff: false
+  notify: Restart admitted clock authority
+- name: Install prebuilt read-only kernel-health probe
+  ansible.builtin.copy:
+    src: "{{ railiance_clock_wheelhouse }}/railiance-clock-kernel-health"
+    dest: "{{ railiance_clock_install_root }}/kernel-health"
+    owner: root
+    group: root
+    mode: '0755'
+- name: Write non-secret authority and health policy configuration
+  ansible.builtin.template:
+    src: "{{ item }}.json.j2"
+    dest: "{{ railiance_clock_install_root }}/{{ item }}.json"
+    owner: root
+    group: root
+    mode: '0644'
+  loop: [authority, health-policy]
+  notify: Restart admitted clock authority
+- name: Install host service units
+  ansible.builtin.template:
+    src: "{{ item }}.j2"
+    dest: "/etc/systemd/system/{{ item }}"
+    owner: root
+    group: root
+    mode: '0644'
+  loop: [railiance-clock.service, railiance-clock-health.service, railiance-clock-health.timer]
+  notify: Reload clock service units
+- name: Load changed units before starting
+  ansible.builtin.meta: flush_handlers
+- name: Export current host health
+  ansible.builtin.systemd:
+    name: railiance-clock-health.service
+    state: started
+- name: Enable bounded periodic host-health export
+  ansible.builtin.systemd:
+    name: railiance-clock-health.timer
+    enabled: true
+    state: started
+- name: Enable private authority
+  ansible.builtin.systemd:
+    name: railiance-clock.service
+    enabled: true
+    state: started
+- name: Verify usable authority independently of service liveness
+  ansible.builtin.uri:
+    url: http://127.0.0.1:8787/readyz
+    return_content: true
+    status_code: 200
+  register: clock_ready
+  retries: 3
+  delay: 2
+  until: clock_ready.status == 200
diff --git a/ansible/roles/railiance_clock/tasks/main.yaml b/ansible/roles/railiance_clock/tasks/main.yaml
new file mode 100644
index 0000000..8c01292
--- /dev/null
+++ b/ansible/roles/railiance_clock/tasks/main.yaml
@@ -0,0 +1,50 @@
+---
+- name: Converge explicitly admitted Railiance Clock host scope
+  when: railiance_clock_enabled | bool
+  block:
+    - name: Require supported host and concrete admission
+      ansible.builtin.assert:
+        that:
+          - ansible_system == 'Linux'
+          - ansible_distribution == 'Ubuntu'
+          - ansible_distribution_major_version == '24'
+          - railiance_clock_admission_ref | length > 0
+          - railiance_clock_upstreams | length > 0
+          - railiance_clock_host_drift_ppm | int >= 500
+          - railiance_clock_max_error_ns | int > railiance_clock_measurement_margin_ns | int
+    - name: Gather service facts without changing clocks
+      ansible.builtin.service_facts:
+    - name: Refuse competing discipline daemons
+      ansible.builtin.assert:
+        that:
+          - ansible_facts.services.get(item, {}).get('state', 'stopped') != 'running'
+      loop: [chrony.service, chronyd.service, ntp.service, ntpd.service]
+    - name: Ensure the existing time daemon is installed
+      ansible.builtin.assert:
+        that: "'systemd-timesyncd.service' in ansible_facts.services"
+    - name: Configure reviewed timesyncd baseline only when explicitly selected
+      when: railiance_clock_manage_timesyncd | bool
+      block:
+        - name: Create timesyncd configuration directory
+          ansible.builtin.file:
+            path: /etc/systemd/timesyncd.conf.d
+            state: directory
+            owner: root
+            group: root
+            mode: '0755'
+        - name: Install sole owner drop-in
+          ansible.builtin.template:
+            src: timesyncd.conf.j2
+            dest: /etc/systemd/timesyncd.conf.d/60-railiance-clock.conf
+            owner: root
+            group: root
+            mode: '0644'
+          notify: Restart reviewed timesyncd
+        - name: Keep admitted daemon enabled
+          ansible.builtin.systemd:
+            name: systemd-timesyncd
+            enabled: true
+            state: started
+    - name: Install authority and health export
+      when: railiance_clock_authority_enabled | bool
+      ansible.builtin.include_tasks: authority.yaml
diff --git a/ansible/roles/railiance_clock/templates/authority.json.j2 b/ansible/roles/railiance_clock/templates/authority.json.j2
new file mode 100644
index 0000000..d8ba60c
--- /dev/null
+++ b/ansible/roles/railiance_clock/templates/authority.json.j2
@@ -0,0 +1 @@
+{{ {'private_key_file': railiance_clock_state_root + '/signing.pem', 'health_file': railiance_clock_health_root + '/health.json', 'health_owner_uid': 0, 'authority_id': 'railiance01', 'environment': 'prod', 'kid': railiance_clock_kid, 'policy_id': railiance_clock_policy_id, 'port': 8787, 'max_health_age_ns': 10000000000, 'host_drift_ppm': railiance_clock_host_drift_ppm | int, 'max_error_ns': railiance_clock_max_error_ns | int, 'max_continuity_error_ns': 50000000, 'max_sample_age_ns': 5000000000} | to_nice_json }}
diff --git a/ansible/roles/railiance_clock/templates/health-policy.json.j2 b/ansible/roles/railiance_clock/templates/health-policy.json.j2
new file mode 100644
index 0000000..40d2def
--- /dev/null
+++ b/ansible/roles/railiance_clock/templates/health-policy.json.j2
@@ -0,0 +1 @@
+{{ {'status': 'admitted', 'policy_id': railiance_clock_policy_id, 'upstreams': railiance_clock_upstreams, 'kernel_helper': railiance_clock_install_root + '/kernel-health', 'max_error_ns': railiance_clock_max_error_ns | int, 'measurement_margin_ns': railiance_clock_measurement_margin_ns | int, 'host_drift_ppm': railiance_clock_host_drift_ppm | int, 'admission_ref': railiance_clock_admission_ref} | to_nice_json }}
diff --git a/ansible/roles/railiance_clock/templates/railiance-clock-health.service.j2 b/ansible/roles/railiance_clock/templates/railiance-clock-health.service.j2
new file mode 100644
index 0000000..414215e
--- /dev/null
+++ b/ansible/roles/railiance_clock/templates/railiance-clock-health.service.j2
@@ -0,0 +1,18 @@
+[Unit]
+Description=Read-only Railiance host clock quality export
+After=systemd-timesyncd.service
+[Service]
+Type=oneshot
+ExecStart={{ railiance_clock_install_root }}/venv/bin/railiance-clock health-export --policy {{ railiance_clock_install_root }}/health-policy.json --output {{ railiance_clock_health_root }}/health.json
+User=root
+NoNewPrivileges=yes
+CapabilityBoundingSet=
+AmbientCapabilities=
+ProtectSystem=strict
+ReadWritePaths={{ railiance_clock_health_root }}
+ProtectHome=yes
+PrivateTmp=yes
+ProtectClock=yes
+RestrictAddressFamilies=AF_UNIX
+TimeoutStartSec=12
+UMask=0022
diff --git a/ansible/roles/railiance_clock/templates/railiance-clock-health.timer.j2 b/ansible/roles/railiance_clock/templates/railiance-clock-health.timer.j2
new file mode 100644
index 0000000..c3a2840
--- /dev/null
+++ b/ansible/roles/railiance_clock/templates/railiance-clock-health.timer.j2
@@ -0,0 +1,9 @@
+[Unit]
+Description=Refresh Railiance host clock health
+[Timer]
+OnBootSec=2
+OnUnitActiveSec=2
+AccuracySec=100ms
+Unit=railiance-clock-health.service
+[Install]
+WantedBy=timers.target
diff --git a/ansible/roles/railiance_clock/templates/railiance-clock.service.j2 b/ansible/roles/railiance_clock/templates/railiance-clock.service.j2
new file mode 100644
index 0000000..f7c4ffa
--- /dev/null
+++ b/ansible/roles/railiance_clock/templates/railiance-clock.service.j2
@@ -0,0 +1,29 @@
+[Unit]
+Description=Private Railiance application time authority
+After=network.target railiance-clock-health.service
+Requires=railiance-clock-health.service
+[Service]
+User=railiance-clock
+Group=railiance-clock
+ExecStart={{ railiance_clock_install_root }}/venv/bin/railiance-clock serve --config {{ railiance_clock_install_root }}/authority.json
+NoNewPrivileges=yes
+CapabilityBoundingSet=
+AmbientCapabilities=
+ProtectSystem=strict
+ProtectHome=yes
+PrivateTmp=yes
+PrivateDevices=yes
+ProtectClock=yes
+ProtectKernelTunables=yes
+ProtectKernelModules=yes
+ProtectControlGroups=yes
+RestrictAddressFamilies=AF_INET AF_INET6
+IPAddressDeny=any
+IPAddressAllow=localhost
+MemoryMax=128M
+TasksMax=32
+UMask=0077
+Restart=on-failure
+RestartSec=5
+[Install]
+WantedBy=multi-user.target
diff --git a/ansible/roles/railiance_clock/templates/timesyncd.conf.j2 b/ansible/roles/railiance_clock/templates/timesyncd.conf.j2
new file mode 100644
index 0000000..1d5fa50
--- /dev/null
+++ b/ansible/roles/railiance_clock/templates/timesyncd.conf.j2
@@ -0,0 +1,7 @@
+# Managed by railiance-infra; {{ railiance_clock_admission_ref }}.
+[Time]
+NTP={{ railiance_clock_upstreams | join(' ') }}
+FallbackNTP=
+PollIntervalMinSec=32
+PollIntervalMaxSec=64
+RootDistanceMaxSec=500ms
diff --git a/workplans/RAIL-HO-WP-0013-host-time-baseline.md b/workplans/RAIL-HO-WP-0013-host-time-baseline.md
index 0800e1b..542f845 100644
--- a/workplans/RAIL-HO-WP-0013-host-time-baseline.md
+++ b/workplans/RAIL-HO-WP-0013-host-time-baseline.md
@@ -4,7 +4,7 @@ type: workplan
 title: "Declare and verify the Railiance host UTC baseline"
 domain: financials
 repo: railiance-infra
-status: ready
+status: active
 flavor: planning
 owner: codex
 topic_slug: railiance
@@ -49,7 +49,7 @@ Define what source health can honestly claim before exposing it to the clock app
 
 ```task
 id: RAIL-HO-WP-0013-T02
-status: wait
+status: progress
 priority: high
 state_hub_task_id: "75f17ffa-b781-549d-82ce-d19d431c2618"
 ```
@@ -92,3 +92,10 @@ IaC to apply/read back. Reverify usable host health and no extra listener/daemon
 record rollback and monitoring ownership. Hand evidence to RCLK-WP-0005 and
 railiance-bootstrap for ordering/rehearsal. Keep all residuals live before closure.
 No corporate workstation time settings or app-clock trust adoption in this plan.
+
+
+2026-09-15: operator requested implementation and consumer use. Added opt-in
+railiance_clock owner role and host-time playbook; bootstrap invokes the same
+role. Authority activation requires artifact hash, admission reference and
+explicit signing-key delivery. Defaults change no clocks and deploy no service.
+Native convergence, custody and measured UTC policy acceptance remain open.