Smooth Hermes TTS sentence transitions

platform/docker/tts-gateway/tts_gateway.py

@@ -224,6 +224,40 @@ def _spoken_date(match: re.Match) -> str:
     return result
 
 
+def _spoken_short_date_range(match: re.Match) -> str:
+    first_day = int(match.group(1))
+    last_day = int(match.group(2))
+    month = int(match.group(3))
+    year = match.group(4)
+    month_name = GERMAN_MONTHS.get(month)
+    if not month_name or not 1 <= first_day <= 31 or not 1 <= last_day <= 31:
+        return match.group(0)
+    result = f"{first_day}. bis {last_day}. {month_name}"
+    if year:
+        result += f" {year}"
+    return result
+
+
+def _spoken_full_date_range(match: re.Match) -> str:
+    first_day = int(match.group(1))
+    first_month = int(match.group(2))
+    last_day = int(match.group(3))
+    last_month = int(match.group(4))
+    year = match.group(5)
+    first_name = GERMAN_MONTHS.get(first_month)
+    last_name = GERMAN_MONTHS.get(last_month)
+    if (not first_name or not last_name
+            or not 1 <= first_day <= 31 or not 1 <= last_day <= 31):
+        return match.group(0)
+    if first_month == last_month:
+        result = f"{first_day}. bis {last_day}. {last_name}"
+    else:
+        result = f"{first_day}. {first_name} bis {last_day}. {last_name}"
+    if year:
+        result += f" {year}"
+    return result
+
+
 def _spell_digits(value: str) -> str:
     return " ".join(GERMAN_DIGITS[digit] for digit in value)
 
@@ -277,6 +311,20 @@ def normalize_for_german_speech(text: str) -> str:
         text,
         flags=re.IGNORECASE,
     )
+    # Date ranges are deliberately strict: both variants require dotted
+    # calendar notation, so ordinary numeric ranges remain untouched.
+    text = re.sub(
+        r"\b([0-3]?\d)\.([01]?\d)\.\s*[-‐‑‒–—−]\s*"
+        r"([0-3]?\d)\.([01]?\d)\.(?:(\d{4})\b)?",
+        _spoken_full_date_range,
+        text,
+    )
+    text = re.sub(
+        r"\b([0-3]?\d)\.\s*[-‐‑‒–—−]\s*"
+        r"([0-3]?\d)\.([01]?\d)\.(?:(\d{4})\b)?",
+        _spoken_short_date_range,
+        text,
+    )
     text = re.sub(
         r"\b([0-3]?\d)\.([01]?\d)\.(?:(\d{4})\b)?",
         _spoken_date,