diff --git a/plugins/prometheus/routes.py b/plugins/prometheus/routes.py
index 0d79c9a..d5db334 100644
--- a/plugins/prometheus/routes.py
+++ b/plugins/prometheus/routes.py
@@ -20,7 +20,7 @@ from steward.models.users import UserRole
 from . import library
 from .models import PrometheusTarget, PrometheusWidgetTemplate
 from .scraper import ScrapeError, scrape
-from .service import (OWN_METRICS, SOURCE, FormError, fold_states, form_values, map_families,
+from .service import (OWN_METRICS, SOURCE, FormError, fold_states, form_values, is_moment, map_families,
                       parse_form, patterns, shown_value, target_state)
 
 prometheus_bp = Blueprint("prometheus", __name__, template_folder="templates")
@@ -325,7 +325,7 @@ async def series_detail(target_id: str):
         series = await points(db, SOURCE, resource, metric,
                               datetime.now(timezone.utc) - timedelta(hours=hours))
     labels = resource[len(target.name) + 1:] if resource != target.name else ""
-    stamp_axis = metric.endswith("_timestamp_seconds")
+    stamp_axis = is_moment(metric)
     return await render_template(
         "prometheus/series.html", target=target, resource=resource, metric=metric, labels=labels,
         now=shown_value(metric, now_row.value if now_row else None), hours=hours, ranges=RANGES,
diff --git a/plugins/prometheus/service.py b/plugins/prometheus/service.py
index 7f39569..9b33acf 100644
--- a/plugins/prometheus/service.py
+++ b/plugins/prometheus/service.py
@@ -122,13 +122,23 @@ def fold_states(metric: str, rows: list[dict]) -> list[dict] | None:
     return folded
 
 
+# A series named for a moment holds Unix seconds, not a span of time: the
+# convention's *_timestamp_seconds, and the *_time_seconds some exporters use
+# (Home Assistant's homeassistant_last_updated_time_seconds).
+MOMENT_SUFFIXES = ("_timestamp_seconds", "_time_seconds")
+
+
+def is_moment(metric: str) -> bool:
+    return metric.endswith(MOMENT_SUFFIXES)
+
+
 def shown_value(metric: str, value: float | None) -> dict:
     """A series' value in its unit, from the Prometheus naming conventions.
-    A *_timestamp_seconds is a moment: it comes back as `moment` for the page
-    to show as "3m ago" in the reader's zone; 0 there means "never"."""
+    A moment (is_moment) comes back as `moment` for the page to show as
+    "3m ago" in the reader's zone; 0 there means "never"."""
     if value is None:
         return {"text": "—", "moment": None}
-    if metric.endswith("_timestamp_seconds"):
+    if is_moment(metric):
         if value <= 0:
             return {"text": "never", "moment": None}
         return {"text": "", "moment": datetime.fromtimestamp(value, timezone.utc)}
@@ -184,11 +194,12 @@ def map_families(target: str, families: dict[str, prometheus.Family], keep: list
 # ── The form ─────────────────────────────────────────────────────────────────
 
 def patterns(text: str) -> list[str]:
-    """Name patterns from a textarea: one per line or comma-separated."""
+    """Name patterns from a textarea: one per line, or separated by commas or
+    spaces. A metric name never holds whitespace, so a paste that turned line
+    breaks into spaces still reads as the patterns it was."""
     out: list[str] = []
-    for line in (text or "").replace(",", "\n").splitlines():
-        p = line.strip()
-        if p and p not in out:
+    for p in (text or "").replace(",", " ").split():
+        if p not in out:
             out.append(p)
     return out
 
diff --git a/plugins/prometheus/templates/prometheus/series.html b/plugins/prometheus/templates/prometheus/series.html
index 3d99b25..0885ffd 100644
--- a/plugins/prometheus/templates/prometheus/series.html
+++ b/plugins/prometheus/templates/prometheus/series.html
@@ -1,6 +1,7 @@
 {# plugins/prometheus/templates/prometheus/series.html — one stored series
    of a target (milestone 506): its newest value and a chart over a chosen
-   range. A *_timestamp_seconds series charts as moments, not numbers. #}
+   range. A moment series (*_timestamp_seconds, *_time_seconds) charts as
+   moments, not numbers. #}
 {% extends "base.html" %}
 {% from "_macros.html" import crumbs, page_header %}
 {% block title %}{{ metric }} — {{ target.name }} — Steward{% endblock %}
diff --git a/tests/plugins/prometheus/test_pages.py b/tests/plugins/prometheus/test_pages.py
index c4267e5..c90a672 100644
--- a/tests/plugins/prometheus/test_pages.py
+++ b/tests/plugins/prometheus/test_pages.py
@@ -72,6 +72,9 @@ def test_series_are_grouped_by_metric_with_their_labels_and_units():
         ("target=S", "fresh", ["fresh", "late"])]
     assert groups[2]["rows"][0]["resource"] == "A:target=S,state=fresh"
     assert shown_value("x_timestamp_seconds", 0) == {"text": "never", "moment": None}
+    # Home Assistant names its Unix times *_time_seconds (#6423): a moment, not "20751d 21h".
+    assert shown_value("homeassistant_last_updated_time_seconds", 1792964340.0) == {
+        "text": "", "moment": datetime.fromtimestamp(1792964340.0, timezone.utc)}
     assert shown_value("jobs_per_sec", 0.25)["text"] == "0.25/s"
     assert shown_value("job_seconds", 90)["text"] == "1m 30s"
     assert shown_value("anything", None)["text"] == "—"
diff --git a/tests/plugins/prometheus/test_service.py b/tests/plugins/prometheus/test_service.py
index dda8e14..8467c71 100644
--- a/tests/plugins/prometheus/test_service.py
+++ b/tests/plugins/prometheus/test_service.py
@@ -73,6 +73,10 @@ def test_names():
     assert resource_for("T", ()) == "T"
     assert resource_for("T", (("a", "1"), ("b", "x"))) == "T:a=1,b=x"
     assert patterns("a_*, b_*\n\n a_* \nc") == ["a_*", "b_*", "c"]
+    # A paste that turned its line breaks into spaces (#6423): no metric name
+    # holds whitespace, so each word is a pattern.
+    assert patterns("ha_last_updated_time_seconds  ha_entity_available\tha_entity_info") == [
+        "ha_last_updated_time_seconds", "ha_entity_available", "ha_entity_info"]
 
 
 def test_labels_read_back_as_stored_even_with_a_comma_in_a_value():