diff --git a/skills/usage/SKILL.md b/skills/usage/SKILL.md
index 2efcd58..50d8fd4 100644
--- a/skills/usage/SKILL.md
+++ b/skills/usage/SKILL.md
@@ -8,38 +8,49 @@ description: >
 
 # Usage
 
-Zobrazí spotřebu kreditů na Ollama Cloud pro aktuální API klíč.
+Shows Ollama Cloud credit usage for the current API key.
 
-## Spuštění
+## Run
 
 ```bash
 uv run skills/usage/scripts/ollama_usage.py
 ```
 
-Skript čte `OLLAMA_API_KEY` z `workspace/.env` (vytvořeného uživatelem).
-Pokud chybí nebo klíč nefunguje (401/403), řekni to uživateli — nescrapuj web.
+The script reads `OLLAMA_API_KEY` from the `workspace/.env` file (created by
+the user). If it is missing or the key fails (401/403), tell the user —
+never scrape the website.
 
-## Výstup
+## Output
 
-Text v češtině, přesně tento formát:
+Format (script prints it, present it to the user as-is):
 
-- `Session: <value> %, resets in X hours — <model> (<req count>), …`
-- `Weekly:  <value> %, resets in Y days — <model> (<req count>), …`
-- `Modely (počet požadavků, weekly okno):` — seznam modelů s requesty
+```
+Ollama Cloud usage
+Session: <pct> %, resets in X hours — <model> (<req count>), …
+Weekly:  <pct> %, resets in Y days — <model> (<req count>), …
+Models (request count, weekly window):
+  <model>: <count>
+```
 
-## Reset časy — odvození, ne API
+Present the script output to the user in Czech (translate the labels, keep
+the numbers exact).
 
-`/api/usage` **neobsahuje reset timestamps** (ty existují jen v HTML UI).
-Skript je počítá: session = do další celé hodiny UTC (dashboard ukazuje
-„Resets in 1 hour"), weekly = do nejbližšího pondělí 00:00 UTC.
-Důvod: session usage šel v testu nahoru během pár minut (rolling okno),
-weekly se mění pomalu, konzistentní s hodinovým/týdenním oknem.
-Kdyby se ukázalo, že okno není kalendářové, uprav `until_next_*`.
+## Reset times — derived, not from the API
 
-## Poznámky
+`/api/usage` contains **no reset timestamps** (they exist only in the HTML
+UI). The script computes them: session = until the next full hour UTC (the
+dashboard shows "Resets in 1 hour"), weekly = until the next Monday 00:00
+UTC. Rationale: session usage climbed in real time during testing (rolling
+window), weekly changes slowly — consistent with hourly/weekly windows.
+If the window turns out not to be calendar-based, fix `until_next_*`.
 
-- Endpoint: `GET https://ollama.com/api/usage`, hlavička
-  `Authorization: Bearer <key>` (ověřeno 2026-09, issue #15132 je zastaralá).
-- `limits.*.usage` je zlomek limitu plánu (× 100 = % jako na dashboardu).
-- `activity.cost` u Pro plánu vrací $0.00000 — nefunkční, ve výstupu vynechán.
-- Klíč z `~/.ollama/id_ed25519` nefunguje — jen API key z ollama.com.
\ No newline at end of file
+## Notes
+
+- Endpoint: `GET https://ollama.com/api/usage`, header
+  `Authorization: Bearer <key>` (verified 2026-09; issue #15132 is stale).
+- `limits.*.usage` is a fraction of the plan limit (× 100 = % as on the
+  dashboard).
+- `activity.cost` returns $0.00000 on the Pro plan — broken, omitted from
+  the output.
+- The `~/.ollama/id_ed25519` key does not work — only an API key minted at
+  ollama.com/settings/keys.
\ No newline at end of file
diff --git a/skills/usage/scripts/ollama_usage.py b/skills/usage/scripts/ollama_usage.py
index caabec7..d186238 100644
--- a/skills/usage/scripts/ollama_usage.py
+++ b/skills/usage/scripts/ollama_usage.py
@@ -25,7 +25,7 @@ def load_api_key() -> str:
             line = line.strip()
             if line.startswith("OLLAMA_API_KEY="):
                 return line.split("=", 1)[1].strip().strip('"').strip("'")
-    sys.exit("OLLAMA_API_KEY nenalezen (ani env, ani workspace/.env)")
+    sys.exit("OLLAMA_API_KEY not found (neither env nor workspace/.env)")
 
 
 def fmt_models(models: list[dict]) -> str:
@@ -54,8 +54,8 @@ def fmt_delta_short(td: timedelta) -> str:
     if total >= 86400:
         return f"{int(total // 86400)} days"
     if total >= 3600:
-        return f"{round(total / 3600)} hours"
-    return f"{max(1, round(total / 60))} minutes"
+        return f"{round(td.total_seconds() / 3600)} hours"
+    return f"{max(1, round(td.total_seconds() / 60))} minutes"
 
 
 def main() -> None:
@@ -67,16 +67,16 @@ def main() -> None:
         with urllib.request.urlopen(req, timeout=15) as resp:
             data = json.load(resp)
     except urllib.error.HTTPError as e:
-        sys.exit(f"ollama.com API chyba: HTTP {e.code}")
+        sys.exit(f"ollama.com API error: HTTP {e.code}")
     except urllib.error.URLError as e:
-        sys.exit(f"ollama.com nedostupné: {e.reason}")
+        sys.exit(f"ollama.com unreachable: {e.reason}")
 
     limits = data.get("limits", {})
     session = limits.get("session", {})
     weekly = limits.get("weekly", {})
     now = datetime.now(timezone.utc)
 
-    print("Ollama Cloud — spotřeba")
+    print("Ollama Cloud usage")
     s_models = fmt_models(session.get("models", []))
     print(
         f'Session: {session.get("usage", 0) * 100:.1f} %, '
@@ -92,7 +92,7 @@ def main() -> None:
 
     models = weekly.get("models", [])
     if models:
-        print("Modely (počet požadavků, weekly okno):")
+        print("Models (request count, weekly window):")
         for m in models:
             print(f'  {m["name"]}: {m["request_count"]}')