diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index 1e3ec37..f5700b6 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -206,6 +206,10 @@ jobs:
           # tini is PID 1, so zombies are reaped and SIGTERM reaches Steward.
           test "$(docker exec "$SMOKE-app" cat /proc/1/comm)" = "tini"
 
+          # The zone database is in the image, so a reader's zone resolves
+          # instead of quietly falling back to UTC (milestone 490).
+          docker exec "$SMOKE-app" python -c 'from zoneinfo import ZoneInfo; ZoneInfo("America/New_York")'
+
           # A fresh database lands on first-run setup: a real page, its assets
           # served by Steward itself, and no third-party host in it (rule 155).
           fetch / > /tmp/smoke-page.html
diff --git a/Dockerfile b/Dockerfile
index 62b906c..dd6cdef 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,6 +16,9 @@ RUN DEBIAN_FRONTEND=noninteractive apt-get update \
         # tini — PID 1: reaps the zombies ssh and ansible leave behind and
         # forwards SIGTERM to Steward so a stop is a graceful shutdown
         tini \
+        # tzdata — the zone database, so times show in each reader's own zone
+        # (milestone 490); Debian's slim base no longer carries it
+        tzdata \
     && rm -rf /var/lib/apt/lists/*
 
 # Upgrade pip to suppress the version notice
diff --git a/steward/account/__init__.py b/steward/account/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/steward/account/routes.py b/steward/account/routes.py
new file mode 100644
index 0000000..86dacbe
--- /dev/null
+++ b/steward/account/routes.py
@@ -0,0 +1,84 @@
+"""The signed-in user's own account (milestone 490): the time zone every
+page writes its times in. Any role reaches it, for themselves only."""
+from __future__ import annotations
+
+from itertools import groupby
+
+from quart import Blueprint, abort, current_app, redirect, render_template, request, session
+
+from steward.auth.middleware import require_role
+from steward.core import formatting
+from steward.models.users import User, UserRole
+
+account_bp = Blueprint("account", __name__, url_prefix="/account")
+
+_SOURCES = {"local": "a Steward password", "ldap": "LDAP", "oidc": "single sign-on"}
+
+
+def _zones_by_region() -> list[tuple[str, list[str]]]:
+    """The Account page's choices: UTC alone, then every zone under its
+    region ('America', 'Europe', …)."""
+    named = [z for z in formatting.zone_names() if "/" in z]
+    return [("", ["UTC"])] + [(region, list(zones)) for region, zones
+                              in groupby(named, key=lambda z: z.split("/", 1)[0])]
+
+
+async def _me(db) -> User:
+    # A share link opens widgets read-only; it has no account.
+    user_id = session.get("user_id")
+    if not user_id:
+        abort(403)
+    user = await db.get(User, user_id)
+    if user is None:
+        abort(403)
+    return user
+
+
+@account_bp.get("/")
+@require_role(UserRole.viewer)
+async def account(error: str | None = None, status: int = 200):
+    async with current_app.db_sessionmaker() as db:
+        user = await _me(db)
+    tz = formatting.zone(user.time_zone)
+    return await render_template(
+        "account/index.html", user=user, source=_SOURCES.get(user.auth_source, user.auth_source),
+        zone_name=user.time_zone or "UTC", zone_label=formatting.tz_label(tz),
+        zones=_zones_by_region(), error=error), status
+
+
+@account_bp.post("/")
+@require_role(UserRole.viewer)
+async def account_save():
+    from steward.core.audit import log_audit
+    name = ((await request.form).get("time_zone") or "").strip()
+    if name not in formatting.zone_names():
+        return await account(f"{name or 'That'} is not a time zone Steward knows.", 400)
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            user = await _me(db)
+            before = user.time_zone
+            user.time_zone = name
+    session["tz"] = name
+    if before != name:
+        await log_audit(current_app, user.id, user.username, "account.time_zone",
+                        detail={"time_zone": name, "was": before or "UTC"})
+    return redirect("/account/")
+
+
+@account_bp.post("/time-zone/adopt")
+@require_role(UserRole.viewer)
+async def adopt_time_zone():
+    """The browser's zone, saved for an account that has none yet: base.html
+    sends it once, on the first page after a sign-in without one. A zone set
+    on the Account page is never replaced. Answers whether it was saved."""
+    name = ((await request.get_json(silent=True)) or {}).get("time_zone") or ""
+    if name not in formatting.zone_names():
+        return {"adopted": False}, 400
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            user = await _me(db)
+            if user.time_zone is not None:
+                return {"adopted": False}
+            user.time_zone = name
+    session["tz"] = name
+    return {"adopted": True}
diff --git a/steward/app.py b/steward/app.py
index 4bd99ef..3143b5a 100644
--- a/steward/app.py
+++ b/steward/app.py
@@ -138,7 +138,15 @@ def create_app(
     app.jinja_env.filters["bytes"] = _fmt.human_bytes
     app.jinja_env.filters["rate"] = _fmt.human_rate
     app.jinja_env.filters["duration"] = _fmt.human_duration
-    app.jinja_env.filters["ago"] = _fmt.ago
+    # A moment is written in the reader's zone, saved on their account and held
+    # in the session (milestone 490); outside a request (an email, a report)
+    # it is UTC.
+    def _viewer_zone():
+        from quart import has_request_context, session
+        return _fmt.zone(session.get("tz")) if has_request_context() else _fmt.zone(None)
+    app.jinja_env.filters["ago"] = lambda moment, now=None: _fmt.ago(moment, now, tz=_viewer_zone())
+    app.jinja_env.filters["when"] = lambda moment: _fmt.when(moment, _viewer_zone())
+    app.jinja_env.globals["tz_label"] = lambda: _fmt.tz_label(_viewer_zone())
     app.jinja_env.globals["status_class"] = (
         lambda value, kind: _fmt.status_class(value, kind, app.config.get("THRESHOLDS", {}))
     )
@@ -211,6 +219,7 @@ def create_app(
     from .settings.routes import settings_bp
     from .audit.routes import audit_bp
     from .ai_access.routes import ai_access_bp
+    from .account.routes import account_bp
 
     app.register_blueprint(auth_bp)
     app.register_blueprint(dashboard_bp)
@@ -223,6 +232,7 @@ def create_app(
     app.register_blueprint(settings_bp)
     app.register_blueprint(audit_bp)
     app.register_blueprint(ai_access_bp)
+    app.register_blueprint(account_bp)
 
     # Register the unified Monitor status source for the Status page. Plugins
     # may register additional sources from setup(). Idempotent.
diff --git a/steward/audit/service.py b/steward/audit/service.py
index 66cf5bc..f647f4c 100644
--- a/steward/audit/service.py
+++ b/steward/audit/service.py
@@ -92,6 +92,7 @@ ACTIONS = {
     "auth.login": "signed in",
     "auth.login_failed": "failed to sign in",
     "auth.setup": "set up Steward",
+    "account.time_zone": "set their time zone",
     "host.created": "added host",
     "host.renamed": "renamed host",
     "host.deleted": "deleted host",
@@ -143,7 +144,7 @@ ACTIONS = {
 }
 
 # The filter's choices: an area, matched as a prefix of the action code.
-AREAS = (("auth.", "Sign-ins"), ("host.", "Hosts"), ("monitor.", "Monitors"),
+AREAS = (("auth.", "Sign-ins"), ("account.", "Accounts"), ("host.", "Hosts"), ("monitor.", "Monitors"),
          ("alert_rule.", "Alert rules"), ("maintenance_window.", "Maintenance"),
          ("ansible.run", "Playbook runs"), ("ansible.", "Ansible (all)"),
          ("settings.", "Settings"), ("plugin.", "Plugins"), ("api_token.", "AI access"),
diff --git a/steward/auth/middleware.py b/steward/auth/middleware.py
index f0842d0..48456cd 100644
--- a/steward/auth/middleware.py
+++ b/steward/auth/middleware.py
@@ -117,6 +117,7 @@ def login_user(user) -> None:
     session["user_id"] = user.id
     session["user_role"] = user.role.value
     session["username"] = user.username
+    session["tz"] = user.time_zone
     session["login_at"] = time.time()
 
 
@@ -127,7 +128,7 @@ async def refresh_session_user() -> None:
     it began (not since the last request: the cookie is re-signed on every
     response, so the cookie's own age would let an active session live
     forever). A user who has been deleted or deactivated is logged out on
-    their next request, and a role change applies at once.
+    their next request, and a role change or a new time zone applies at once.
     """
     user_id = session.get("user_id")
     if not user_id:
@@ -146,6 +147,10 @@ async def refresh_session_user() -> None:
         return
     if session.get("user_role") != user.role.value:
         session["user_role"] = user.role.value
+    # The zone times are written in (milestone 490): a change made on the
+    # Account page, or the browser's zone saved for an account without one.
+    if session.get("tz") != user.time_zone:
+        session["tz"] = user.time_zone
 
 
 def logout_user() -> None:
diff --git a/steward/core/formatting.py b/steward/core/formatting.py
index 5955b6f..d5738a0 100644
--- a/steward/core/formatting.py
+++ b/steward/core/formatting.py
@@ -2,13 +2,17 @@
 
 How Steward writes a size, a rate, a span of time and a moment, and how it
 grades a reading against Settings → Thresholds — once, for every page and
-plugin (#5093). Registered as Jinja filters (|bytes, |rate, |duration, |ago)
-and the status_class global in app.py; Python callers import them from here.
+plugin (#5093). Registered as Jinja filters (|bytes, |rate, |duration, |ago,
+|when) and the status_class global in app.py; Python callers import them from
+here. A moment is written in the reader's own zone, on a 24-hour clock
+(milestone 490); app.py hands the filters the zone saved on their account.
 """
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone, tzinfo
+from functools import lru_cache
 from typing import Any
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError, available_timezones
 
 from markupsafe import Markup, escape
 
@@ -65,9 +69,43 @@ def seconds_since(when: datetime | None, now: datetime | None = None) -> float |
     return ((now or datetime.now(timezone.utc)) - _utc(when)).total_seconds()
 
 
-def ago(when: datetime | None, now: datetime | None = None) -> Markup:
+def zone(name: str | None) -> tzinfo:
+    """The zone a reader asked for by its IANA name, or UTC when none was
+    given or it is not one this machine knows."""
+    if not name:
+        return timezone.utc
+    try:
+        return ZoneInfo(name)
+    except (ZoneInfoNotFoundError, ValueError):
+        return timezone.utc
+
+
+@lru_cache(maxsize=1)
+def zone_names() -> tuple[str, ...]:
+    """Every IANA zone this machine knows, sorted: the Account page's choices,
+    and what a saved zone is checked against."""
+    return tuple(sorted(n for n in available_timezones() if "/" in n or n == "UTC"))
+
+
+def tz_label(tz: tzinfo | None = None, now: datetime | None = None) -> str:
+    """The zone's short name as it stands now ('EDT', 'CET', 'UTC'), for a
+    column header that says which zone its times are in."""
+    return (now or datetime.now(timezone.utc)).astimezone(tz or timezone.utc).tzname() or "UTC"
+
+
+def _exact(local: datetime) -> str:
+    """'Thu 8 Oct 2026 06:58:12 EDT': the full moment, for a hover."""
+    return f"{local:%a} {local.day} {local:%b %Y %H:%M:%S} {local.tzname()}"
+
+
+def _time(when: datetime, local: datetime, text: str) -> Markup:
+    return Markup('<time datetime="{}" title="{}">{}</time>').format(
+        when.strftime("%Y-%m-%dT%H:%M:%SZ"), _exact(local), escape(text))
+
+
+def ago(when: datetime | None, now: datetime | None = None, tz: tzinfo | None = None) -> Markup:
     """'3m ago' (or 'in 3m' for a future moment) in a <time> element whose
-    title is the absolute UTC time, so a hover gives the exact moment."""
+    title is the exact moment in the reader's zone, so a hover gives it."""
     if when is None:
         return Markup(NONE)
     when = _utc(when)
@@ -78,8 +116,31 @@ def ago(when: datetime | None, now: datetime | None = None) -> Markup:
         text = f"{human_duration(secs)} ago"
     else:
         text = f"in {human_duration(-secs)}"
-    return Markup('<time datetime="{}" title="{}">{}</time>').format(
-        when.strftime("%Y-%m-%dT%H:%M:%SZ"), when.strftime("%Y-%m-%d %H:%M:%S UTC"), escape(text))
+    return _time(when, when.astimezone(tz or timezone.utc), text)
+
+
+def when(moment: datetime | None, tz: tzinfo | None = None, now: datetime | None = None) -> Markup:
+    """The exact moment in the reader's zone on a 24-hour clock, as short as
+    it can be read: 'Today 06:58', 'Yesterday 23:41', 'Tomorrow 02:00',
+    'Tue 6 Oct 14:12' this year, '6 Oct 2025 14:12' before it."""
+    if moment is None:
+        return Markup(NONE)
+    tz = tz or timezone.utc
+    moment = _utc(moment)
+    local = moment.astimezone(tz)
+    today = (now or datetime.now(timezone.utc)).astimezone(tz).date()
+    day, hm = local.date(), f"{local:%H:%M}"
+    if day == today:
+        text = f"Today {hm}"
+    elif day == today - timedelta(days=1):
+        text = f"Yesterday {hm}"
+    elif day == today + timedelta(days=1):
+        text = f"Tomorrow {hm}"
+    elif day.year == today.year:
+        text = f"{local:%a} {day.day} {local:%b} {hm}"
+    else:
+        text = f"{day.day} {local:%b} {day.year} {hm}"
+    return _time(moment, local, text)
 
 
 def status_class(value: Any, kind: str, thresholds: dict) -> str:
diff --git a/steward/migrations/versions/0034_user_time_zone.py b/steward/migrations/versions/0034_user_time_zone.py
new file mode 100644
index 0000000..abe6837
--- /dev/null
+++ b/steward/migrations/versions/0034_user_time_zone.py
@@ -0,0 +1,22 @@
+"""The zone each user reads times in (milestone 490)
+
+Revision ID: 0034_user_time_zone
+Revises: 0033_retire_uptime_widget
+Create Date: 2026-10-08
+"""
+from typing import Sequence, Union
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "0034_user_time_zone"
+down_revision: Union[str, None] = "0033_retire_uptime_widget"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column("users", sa.Column("time_zone", sa.String(64), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "time_zone")
diff --git a/steward/models/users.py b/steward/models/users.py
index a1e1ed1..d908f5f 100644
--- a/steward/models/users.py
+++ b/steward/models/users.py
@@ -36,3 +36,7 @@ class User(Base):
     auth_source: Mapped[str] = mapped_column(String(16), nullable=False, default="local", server_default="local")
     # The provider's stable id: the LDAP entry DN, or the OIDC `sub`. None for local users.
     external_id: Mapped[str | None] = mapped_column(String(512), nullable=True)
+    # The IANA zone this user reads times in (milestone 490), e.g.
+    # "America/New_York". Their browser's zone is saved the first time they
+    # sign in without one; they change it on the Account page. None reads as UTC.
+    time_zone: Mapped[str | None] = mapped_column(String(64), nullable=True)
diff --git a/steward/static/steward.css b/steward/static/steward.css
index c93e4db..c6cbc49 100644
--- a/steward/static/steward.css
+++ b/steward/static/steward.css
@@ -97,8 +97,12 @@ code { font-family: var(--fs-font-mono); font-size: 0.875em; background: var(--b
   background: var(--red-dim); color: var(--red); font-size: 0.75rem; font-weight: 500;
   font-variant-numeric: tabular-nums;
 }
-.side-user { border-top: 1px solid var(--border); padding: 0.7rem 1.25rem; }
+.side-user { border-top: 1px solid var(--border); padding: 0.7rem 1.25rem;
+  display: flex; align-items: center; justify-content: space-between; gap: 0.5rem; }
 .side-user form { margin: 0; }
+.side-user a { color: var(--text-muted); font-size: 0.84rem; text-decoration: none;
+  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.side-user a:hover, .side-user a[aria-current="page"] { color: var(--text); }
 .side-user button {
   color: var(--text-muted); font-size: 0.84rem; text-decoration: none;
   display: flex; align-items: center; gap: 0.4rem;
@@ -108,7 +112,8 @@ code { font-family: var(--fs-font-mono); font-size: 0.875em; background: var(--b
 /* Keyboard focus: a clear inset ring on every interactive sidebar element. */
 .sidebar .brand:focus-visible,
 .side-nav a:focus-visible,
-.side-user button:focus-visible {
+.side-user button:focus-visible,
+.side-user a:focus-visible {
   outline: 2px solid var(--accent); outline-offset: -2px; color: var(--text);
 }
 .app-main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
@@ -193,6 +198,7 @@ strong, b, th { font-weight: 500; }
 .filter-bar { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; margin-bottom: 0.75rem; }
 .filter-bar input[type=search] { flex: 1 1 16rem; width: auto; }
 .filter-bar select { width: auto; flex: 0 0 auto; }
+.page-actions .filter-bar { margin: 0; }
 /* A small label that links somewhere, such as a group that filters the list. */
 .chip { display: inline-block; margin: 0.1rem 0.3rem 0.1rem 0; padding: 0.05rem 0.45rem; font-size: 0.75rem;
   color: var(--text-muted); border: 1px solid var(--border); border-radius: var(--fs-radius-sm); white-space: nowrap; }
@@ -219,6 +225,8 @@ strong, b, th { font-weight: 500; }
 /* A second link inside a row that opens as a whole: it sits above the row's target. */
 .table tr.row-link .row-inner { position: relative; z-index: 1; }
 .table td.nowrap { white-space: nowrap; }
+/* An audit entry's details, one fact a line (milestone 490). */
+.audit-facts { font-size: 0.8rem; color: var(--text-muted); }
 .cell-note { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.2rem; }
 /* An alert episode's own transitions, folded under it (#5316). */
 .episode-steps { margin-top: 0.3rem; font-size: 0.8rem; }
diff --git a/steward/templates/account/index.html b/steward/templates/account/index.html
new file mode 100644
index 0000000..d12cdb8
--- /dev/null
+++ b/steward/templates/account/index.html
@@ -0,0 +1,32 @@
+{# account/index.html — the signed-in user's own account (milestone 490): who
+   they are, and the time zone every page writes its times in. #}
+{% extends "base.html" %}
+{% from "_macros.html" import page_header %}
+{% block title %}Your account — Steward{% endblock %}
+{% block content %}
+{{ page_header("Your account") }}
+
+<p class="page-verdict">
+  Signed in as <strong>{{ user.username }}</strong> ({{ user.role.value }}) with {{ source }}
+  · times show in <strong>{{ zone_name }}</strong> ({{ zone_label }})
+</p>
+
+<form method="post" action="/account/" class="form-page">{{ csrf_field() }}
+  <section class="card form-section" aria-labelledby="acct-time">
+    <h2 id="acct-time" class="section-title">Time zone</h2>
+    {% if error %}<p class="field-error" role="alert">{{ error }}</p>{% endif %}
+    <div class="field">
+      <label class="field-label" for="acct-tz">Show times in</label>
+      <select class="input" id="acct-tz" name="time_zone">
+        {% for region, names in zones %}
+        {% if region %}<optgroup label="{{ region }}">{% endif %}
+        {% for z in names %}<option value="{{ z }}"{% if z == zone_name %} selected{% endif %}>{{ z.split('/', 1)[1]|replace('_', ' ') if region else z }}</option>{% endfor %}
+        {% if region %}</optgroup>{% endif %}
+        {% endfor %}
+      </select>
+      <span class="field-hint">Every page writes its times in this zone, on a 24-hour clock.</span>
+    </div>
+  </section>
+  <button type="submit" class="btn">Save</button>
+</form>
+{% endblock %}
diff --git a/steward/templates/audit/_rows.html b/steward/templates/audit/_rows.html
index 5761813..5ab9e07 100644
--- a/steward/templates/audit/_rows.html
+++ b/steward/templates/audit/_rows.html
@@ -4,8 +4,8 @@
       {% for item in events %}
       {% set e = item.event %}
       <tr>
-        <td style="white-space:nowrap;" title="{{ e.timestamp.strftime('%Y-%m-%d %H:%M:%S UTC') }}">{{ e.timestamp|ago }}</td>
-        <td style="font-size:0.85rem;">{{ e.username }}</td>
+        <td class="nowrap">{{ e.timestamp|when }}</td>
+        <td class="nowrap">{{ e.username }}</td>
         <td title="{{ e.action }}">{{ item.action or e.action }}</td>
         <td>
           {% if item.entity %}
@@ -14,11 +14,9 @@
           {% if item.entity.gone %}<span class="field-hint">(deleted)</span>{% endif %}
           {% elif e.entity_type %}<span class="field-hint">{{ e.entity_type|replace('_', ' ') }}</span>{% endif %}
         </td>
-        <td style="font-size:0.8rem;color:var(--text-muted);max-width:340px;">
+        <td class="audit-facts">
           {% for f in item.facts %}
-          <span style="color:var(--text-dim);">{{ f.label }}</span>
-          {% if f.url %}<a href="{{ f.url }}">{{ f.text }}</a>{% else %}{{ f.text }}{% endif %}
-          {% if not loop.last %} &nbsp;·&nbsp; {% endif %}
+          <div><span class="tone-dim">{{ f.label }}</span> {% if f.url %}<a href="{{ f.url }}">{{ f.text }}</a>{% else %}{{ f.text }}{% endif %}</div>
           {% endfor %}
         </td>
       </tr>
diff --git a/steward/templates/audit/list.html b/steward/templates/audit/list.html
index 0731fad..c081e3a 100644
--- a/steward/templates/audit/list.html
+++ b/steward/templates/audit/list.html
@@ -1,10 +1,12 @@
+{# audit/list.html — who changed what, newest first, each moment exact in the
+   reader's own zone (milestone 490): a record is read for when, not how long ago. #}
 {% extends "base.html" %}
 {% from "_macros.html" import page_header, empty_state %}
 {% block title %}Audit log — Steward{% endblock %}
 {% block content %}
 {% call page_header("Audit log", "Who changed what, newest first.") %}
-  <form method="get" style="display:flex;gap:0.5rem;align-items:center;">
-    <select name="action" aria-label="Show only" style="font-size:0.85rem;" onchange="this.form.submit()">
+  <form class="filter-bar" method="get" action="/audit/">
+    <select name="action" aria-label="Show only" onchange="this.form.submit()">
       <option value="">Everything</option>
       {% for prefix, label in areas %}
       <option value="{{ prefix }}" {% if action_filter == prefix %}selected{% endif %}>{{ label }}</option>
@@ -19,7 +21,7 @@
   <table class="table">
     <thead>
       <tr>
-        <th>When</th>
+        <th>When ({{ tz_label() }})</th>
         <th>User</th>
         <th>Did</th>
         <th>What</th>
diff --git a/steward/templates/base.html b/steward/templates/base.html
index f2c108c..95d5bd5 100644
--- a/steward/templates/base.html
+++ b/steward/templates/base.html
@@ -68,8 +68,9 @@
       {% endif %}
     </nav>
     <div class="side-user">
+      <a href="/account/" title="Your account and time zone"{% if _p.startswith('/account') %} aria-current="page"{% endif %}>{{ session.username }}</a>
       <form method="post" action="/logout">{{ csrf_field() }}
-        <button type="submit" title="Log out">⏻ {{ session.username }}</button>
+        <button type="submit" title="Log out" aria-label="Log out">⏻</button>
       </form>
     </div>
   </aside>
@@ -106,6 +107,25 @@ document.addEventListener('keydown', function (e) {
   if (e.key === 'Escape' && document.body.classList.contains('nav-open')) setNavOpen(false);
 });
 </script>
+{% if session.user_id and not session.tz %}
+<script>
+// An account with no time zone yet takes this browser's, once (milestone 490);
+// the page then reloads so its times are written in it.
+(function () {
+  var tz;
+  try { tz = Intl.DateTimeFormat().resolvedOptions().timeZone; } catch (e) { return; }
+  if (!tz) return;
+  fetch('/account/time-zone/adopt', {
+    method: 'POST',
+    headers: {'Content-Type': 'application/json',
+              'X-CSRF-Token': document.querySelector('meta[name="csrf-token"]').content},
+    body: JSON.stringify({time_zone: tz})
+  }).then(function (r) { return r.ok ? r.json() : null; })
+    .then(function (d) { if (d && d.adopted) location.reload(); })
+    .catch(function () {});
+})();
+</script>
+{% endif %}
 
     <main{% block main_class %}{% endblock %}>
         {% if plugin_failures and session.user_role == 'admin' %}
diff --git a/tests/core/test_audit_page.py b/tests/core/test_audit_page.py
index 833356a..1a99109 100644
--- a/tests/core/test_audit_page.py
+++ b/tests/core/test_audit_page.py
@@ -86,3 +86,24 @@ async def test_the_row_says_what_was_done_not_its_code(app):
     assert 'title="monitor.disabled">paused monitor</td>' in page
     assert "dry run</span>" in page and "False" not in page
     assert '<option value="monitor." selected>Monitors</option>' in page
+
+
+async def test_each_entry_shows_its_exact_moment_in_the_readers_zone(app):
+    """Milestone 490: a record is read for when, not how long ago."""
+    from quart import session
+    from steward.core import formatting as f
+    events = [{"event": _ev("host", "h1", "host.renamed"), "detail": {}, "entity": None,
+               "facts": [{"label": "was", "text": "web-0", "url": None},
+                         {"label": "AI token", "text": "#1", "url": None}]}]
+    async with app.test_request_context("/audit/"):
+        session["tz"] = "America/New_York"
+        page = await render_template("audit/list.html", events=events, after=None, action_filter="")
+    ny = f.zone("America/New_York")
+    assert f"<th>When ({f.tz_label(ny)})</th>" in page
+    # 12:00 UTC is 08:00 in New York, and the hover names the zone.
+    assert f'<td class="nowrap">{f.when(events[0]["event"].timestamp, ny)}</td>' in page
+    assert "08:00:00 EDT" in page and " ago<" not in page
+    # One fact a line, labels quiet, and the table on classes.
+    assert '<div><span class="tone-dim">was</span> web-0</div>' in page
+    table = page[page.index('<table class="table">'):]
+    assert "style=" not in table
diff --git a/tests/core/test_formatting.py b/tests/core/test_formatting.py
index 20a6f31..295719a 100644
--- a/tests/core/test_formatting.py
+++ b/tests/core/test_formatting.py
@@ -44,17 +44,59 @@ def test_duration(secs, text):
     (NOW + timedelta(minutes=5), "in 5m"),
     (NOW, "just now"),
 ])
-def test_ago_reads_relative_and_titles_the_absolute_utc_time(when, text):
+def test_ago_reads_relative_and_titles_the_exact_moment(when, text):
     out = str(f.ago(when, now=NOW))
     stamp = when.replace(tzinfo=timezone.utc) if when.tzinfo is None else when
     assert out == (f'<time datetime="{stamp:%Y-%m-%dT%H:%M:%SZ}" '
-                   f'title="{stamp:%Y-%m-%d %H:%M:%S} UTC">{text}</time>')
+                   f'title="{stamp:%a} {stamp.day} {stamp:%b %Y %H:%M:%S} UTC">{text}</time>')
 
 
 def test_ago_of_nothing_and_of_another_zone():
     assert str(f.ago(None)) == "—"
     est = timezone(timedelta(hours=-4))
-    assert 'title="2026-10-06 18:00:00 UTC"' in str(f.ago(NOW.astimezone(est), now=NOW))
+    assert 'title="Tue 6 Oct 2026 18:00:00 UTC"' in str(f.ago(NOW.astimezone(est), now=NOW))
+
+
+# Milestone 490: a moment in the reader's own zone, on a 24-hour clock.
+NY = f.zone("America/New_York")
+
+
+def test_ago_hovers_the_moment_in_the_readers_zone():
+    assert 'title="Tue 6 Oct 2026 13:57:00 EDT">3m ago<' in str(
+        f.ago(NOW - timedelta(minutes=3), now=NOW, tz=NY))
+
+
+@pytest.mark.parametrize("moment, text, title", [
+    (NOW - timedelta(hours=1), "Today 13:00", "Tue 6 Oct 2026 13:00:00 EDT"),
+    # 03:30 UTC on the 6th is 23:30 on the 5th in New York: the zone moves the day.
+    (datetime(2026, 10, 6, 3, 30, tzinfo=timezone.utc), "Yesterday 23:30", "Mon 5 Oct 2026 23:30:00 EDT"),
+    (datetime(2026, 10, 7, 6, 0, tzinfo=timezone.utc), "Tomorrow 02:00", "Wed 7 Oct 2026 02:00:00 EDT"),
+    (datetime(2026, 9, 30, 12, 0, tzinfo=timezone.utc), "Wed 30 Sep 08:00", "Wed 30 Sep 2026 08:00:00 EDT"),
+    # Before this year the year shows; in winter the zone is EST, an hour further back.
+    (datetime(2025, 12, 25, 12, 0, tzinfo=timezone.utc), "25 Dec 2025 07:00", "Thu 25 Dec 2025 07:00:00 EST"),
+    (datetime(2026, 10, 6, 21, 5), "Today 17:05", "Tue 6 Oct 2026 17:05:00 EDT"),  # naive is UTC
+])
+def test_when_writes_the_exact_moment_in_the_readers_zone(moment, text, title):
+    stamp = moment.replace(tzinfo=timezone.utc) if moment.tzinfo is None else moment
+    assert str(f.when(moment, NY, now=NOW)) == (
+        f'<time datetime="{stamp:%Y-%m-%dT%H:%M:%SZ}" title="{title}">{text}</time>')
+
+
+def test_when_is_a_24_hour_clock_and_utc_without_a_zone():
+    assert ">Today 18:00<" in str(f.when(NOW, now=NOW))
+    assert ">Today 23:59<" in str(f.when(NOW.replace(hour=23, minute=59), now=NOW))
+    assert str(f.when(None)) == "—"
+
+
+def test_zone_falls_back_to_utc_and_names_itself():
+    assert f.zone(None) is timezone.utc and f.zone("") is timezone.utc
+    assert f.zone("Not/AZone") is timezone.utc and f.zone("../etc/passwd") is timezone.utc
+    assert f.tz_label(NY, now=NOW) == "EDT"
+    assert f.tz_label(NY, now=datetime(2026, 1, 15, tzinfo=timezone.utc)) == "EST"
+    assert f.tz_label(None) == "UTC"
+    names = f.zone_names()
+    assert "America/New_York" in names and "Europe/London" in names and "UTC" in names
+    assert list(names) == sorted(names)
 
 
 @pytest.mark.parametrize("value, kind, cls", [
diff --git a/tests/integration/test_account_time_zone.py b/tests/integration/test_account_time_zone.py
new file mode 100644
index 0000000..db799c0
--- /dev/null
+++ b/tests/integration/test_account_time_zone.py
@@ -0,0 +1,82 @@
+"""Integration: the zone a user reads times in (milestone 490), against real
+Postgres. The browser's zone is saved for an account without one and never
+over one set by hand; the Account page shows and saves it, refuses a zone
+Steward does not know, and a change reaches the session on the next request.
+Requires STEWARD_DATABASE_URL."""
+from __future__ import annotations
+
+import asyncio
+import os
+import time
+import uuid
+
+import pytest
+
+pytestmark = pytest.mark.integration
+
+
+@pytest.fixture
+def app():
+    if not os.environ.get("STEWARD_DATABASE_URL"):
+        pytest.skip("needs Postgres")
+    from steward.app import create_app
+    return create_app(testing=False)
+
+
+def test_the_browser_zone_is_adopted_once_and_the_account_page_changes_it(app):
+    from steward.models.users import User, UserRole
+
+    async def _go():
+        tag = uuid.uuid4().hex[:8]
+        uid = str(uuid.uuid4())
+        async with app.db_sessionmaker() as s:
+            async with s.begin():
+                s.add(User(id=uid, username=f"tz-{tag}", email=f"tz-{tag}@test",
+                           password_hash="x", role=UserRole.viewer, is_active=True))
+        client = app.test_client()
+        async with client.session_transaction() as sess:
+            sess.update(user_id=uid, user_role="viewer", username=f"tz-{tag}",
+                        login_at=time.time(), _csrf="test-token")
+        csrf = {"X-CSRF-Token": "test-token"}
+
+        async def zone():
+            async with app.db_sessionmaker() as s:
+                return (await s.get(User, uid)).time_zone
+
+        out = {}
+        # No zone yet: every page carries the script that reports the browser's.
+        out["before"] = await (await client.get("/account/")).get_data(as_text=True)
+        out["bogus"] = (await client.post("/account/time-zone/adopt", json={"time_zone": "Mars/Olympus"},
+                                          headers=csrf)).status_code
+        out["adopt"] = await (await client.post("/account/time-zone/adopt",
+                                                json={"time_zone": "America/New_York"},
+                                                headers=csrf)).get_json()
+        out["after_adopt"] = await zone()
+        # A second browser elsewhere does not replace it.
+        out["again"] = await (await client.post("/account/time-zone/adopt",
+                                                json={"time_zone": "Europe/Berlin"},
+                                                headers=csrf)).get_json()
+        out["page"] = await (await client.get("/account/")).get_data(as_text=True)
+        resp = await client.post("/account/", form={"time_zone": "Europe/London"}, headers=csrf)
+        out["save"] = (resp.status_code, resp.headers.get("Location"))
+        out["after_save"] = await zone()
+        resp = await client.post("/account/", form={"time_zone": "Nowhere"}, headers=csrf)
+        out["refused"] = (resp.status_code, await resp.get_data(as_text=True))
+        out["after_refused"] = await zone()
+        async with client.session_transaction() as sess:
+            out["session_tz"] = sess.get("tz")
+        return out
+
+    out = asyncio.run(_go())
+    assert "/account/time-zone/adopt" in out["before"]
+    assert out["bogus"] == 400
+    assert out["adopt"] == {"adopted": True} and out["after_adopt"] == "America/New_York"
+    assert out["again"] == {"adopted": False}
+    page = out["page"]
+    assert "times show in <strong>America/New_York</strong> (E" in page        # EDT or EST
+    assert '<option value="America/New_York" selected>New York</option>' in page
+    assert "/account/time-zone/adopt" not in page                              # nothing left to adopt
+    assert out["save"] == (302, "/account/") and out["after_save"] == "Europe/London"
+    status, body = out["refused"]
+    assert status == 400 and "Nowhere is not a time zone Steward knows." in body
+    assert out["after_refused"] == "Europe/London" and out["session_tz"] == "Europe/London"
diff --git a/tests/test_breadcrumbs.py b/tests/test_breadcrumbs.py
index 7035973..4af568d 100644
--- a/tests/test_breadcrumbs.py
+++ b/tests/test_breadcrumbs.py
@@ -18,6 +18,7 @@ TOP_LEVEL = {
     "steward/templates/ansible/index.html",
     "steward/templates/audit/list.html",
     "steward/templates/ai_access/index.html",
+    "steward/templates/account/index.html",
     "plugins/docker/templates/docker/index.html",
     "plugins/snmp/templates/snmp/index.html",
     "plugins/traefik/templates/traefik/index.html",