diff --git a/app/gibs_map.py b/app/gibs_map.py
index 48d0edb..95e7b18 100644
--- a/app/gibs_map.py
+++ b/app/gibs_map.py
@@ -20,7 +20,7 @@ from __future__ import annotations
 import asyncio
 import re
 import time
-from datetime import date, datetime, timedelta
+from datetime import date, datetime, timedelta, timezone
 
 import httpx
 
@@ -98,9 +98,18 @@ def _parse_time_domain(domain: str) -> dict:
     Returns {min, max, latest, ranges:[{start,end}]} where ranges keep the
     raw GIBS windows so the frontend can warn when a picked date is outside
     every window (GIBS still serves nearest-time tiles, but this is honest).
+
+    GIBS' published windows include the current UTC day as soon as it starts,
+    but daily mosaics (MODIS/VIIRS true color, night lights) aren't actually
+    ingested until hours later — tiles for "today" 404 until then. So we clamp
+    daily-layer window ends to *yesterday* UTC: 'latest' then always points at
+    imagery that really exists.
     """
     windows = []
     min_d, max_d = None, None
+    # 00:00–~03:00+ UTC the newest full day is always yesterday; use a small
+    # margin so we never advertise a same-day mosaic that isn't ingested yet.
+    cutoff = datetime.now(timezone.utc).date() - timedelta(days=1)
     for part in domain.split(","):
         part = part.strip()
         m = _TIME_RANGE_RE.match(part)
@@ -108,6 +117,10 @@ def _parse_time_domain(domain: str) -> dict:
             continue
         start = date.fromisoformat(m.group(1))
         end = date.fromisoformat(m.group(2))
+        if m.group(3) == "P1D" and end > cutoff:
+            end = cutoff
+        if start > end:
+            continue  # whole window was "not yet ingested" days
         windows.append({"start": start.isoformat(), "end": end.isoformat()})
         if min_d is None or start < min_d:
             min_d = start