[HNT-295] fix section date localization

merino/curated_recommendations/localization.py

@@ -1,5 +1,9 @@
 """Hardcoded localized strings."""
 
+from datetime import datetime
+
+from babel.dates import format_date
+
 from merino.curated_recommendations.corpus_backends.protocol import ScheduledSurfaceId
 import logging
 
@@ -72,3 +76,28 @@ def get_translation(surface_id: ScheduledSurfaceId, topic: str, default_topic: s
         return default_topic
 
     return translations[topic]
+
+
+# Localization for Babel date formats based on surface_id.
+SURFACE_ID_TO_LOCALE = {
+    ScheduledSurfaceId.NEW_TAB_EN_US: "en_US",
+    ScheduledSurfaceId.NEW_TAB_EN_GB: "en_GB",
+    ScheduledSurfaceId.NEW_TAB_DE_DE: "de_DE",
+    ScheduledSurfaceId.NEW_TAB_FR_FR: "fr_FR",
+    ScheduledSurfaceId.NEW_TAB_ES_ES: "es_ES",
+    ScheduledSurfaceId.NEW_TAB_IT_IT: "it_IT",
+    ScheduledSurfaceId.NEW_TAB_EN_INTL: "en_IN",  # En-Intl is primarily used in India.
+}
+
+
+def get_localized_date(surface_id: ScheduledSurfaceId, date: datetime) -> str:
+    """Return a localized date string for the given ScheduledSurfaceId.
+
+    Args:
+        surface_id (ScheduledSurfaceId): The New Tab surface ID.
+        date (datetime): The date to be localized.
+
+    Returns:
+        str: Localized date string, for example "December 17, 2024".
+    """
+    return format_date(date, format="long", locale=SURFACE_ID_TO_LOCALE.get(surface_id, "en_US"))

merino/curated_recommendations/provider.py

@@ -3,10 +3,9 @@
 import logging
 import time
 import re
-from datetime import datetime
 from typing import cast
 
-from merino.curated_recommendations import ExtendedExpirationCorpusBackend
+from merino.curated_recommendations import ExtendedExpirationCorpusBackend, CorpusApiBackend
 from merino.curated_recommendations.corpus_backends.protocol import (
     CorpusBackend,
     ScheduledSurfaceId,
@@ -21,7 +20,11 @@
     layout_4_large,
     layout_6_tiles,
 )
-from merino.curated_recommendations.localization import get_translation, LOCALIZED_SECTION_TITLES
+from merino.curated_recommendations.localization import (
+    get_translation,
+    LOCALIZED_SECTION_TITLES,
+    get_localized_date,
+)
 from merino.curated_recommendations.prior_backends.protocol import PriorBackend
 from merino.curated_recommendations.protocol import (
     Locale,
@@ -358,12 +361,15 @@ async def get_sections(
         remaining_recs = general_recs[top_stories_count:]
 
         # Create "Today's top stories" section with the first 6 recommendations
+        surface_date = CorpusApiBackend.get_scheduled_surface_date(
+            CorpusApiBackend.get_surface_timezone(surface_id)
+        )
         feeds = CuratedRecommendationsFeed(
             news_section=Section(
                 receivedFeedRank=0,
                 recommendations=news_recs,
                 title=get_translation(surface_id, "news-section", "In the News"),
-                subtitle=datetime.now().strftime("%B %d, %Y"),  # e.g., "October 24, 2024"
+                subtitle=get_localized_date(surface_id, surface_date),  # e.g., "October 24, 2024"
                 layout=layout_4_large,
             ),
             top_stories_section=Section(

pyproject.toml

@@ -101,6 +101,7 @@ pydantic = "^2.1.0"
 scipy = "^1.14.1"
 orjson = "^3.10.7"
 tenacity = "^9.0.0"
+babel = "^2.16.0"
 
 [tool.poetry.group.jobs.dependencies]
 # Jobs specific dependecies required on top of some of the main dependencies above

tests/integration/api/v1/curated_recommendations/test_curated_recommendations.py

@@ -1446,7 +1446,7 @@ async def test_curated_recommendations_with_sections_feed_boost_followed_section
 
     @pytest.mark.asyncio
     @pytest.mark.parametrize(
-        "locale, expected_titles",
+        "locale, expected_titles, expected_news_subtitle",
         [
             (
                 "en-US",
@@ -1457,6 +1457,7 @@ async def test_curated_recommendations_with_sections_feed_boost_followed_section
                     "education": "Education",
                     "sports": "Sports",
                 },
+                "December 17, 2024",  # Frozen time 2024-12-18 6am UTC = 2024-12-17 10pm PST
             ),
             (
                 "de-DE",
@@ -1467,10 +1468,12 @@ async def test_curated_recommendations_with_sections_feed_boost_followed_section
                     "education": "Bildung",
                     "sports": "Sport",
                 },
+                "18. Dezember 2024",  # Frozen time 2024-12-18 6am UTC = 2024-12-18 7am CET
             ),
         ],
     )
-    async def test_sections_feed_titles(self, locale, expected_titles):
+    @freezegun.freeze_time("2024-12-18 06:00:00", tz_offset=0)
+    async def test_sections_feed_titles(self, locale, expected_titles, expected_news_subtitle):
         """Test the curated recommendations endpoint 'sections' have the expected (sub)titles."""
         async with AsyncClient(app=app, base_url="http://test") as ac:
             # Mock the endpoint to request the sections feed
@@ -1495,7 +1498,7 @@ async def test_sections_feed_titles(self, locale, expected_titles):
             # Ensure "Today's top stories" is present with a valid date subtitle
             news_section = data["feeds"].get("news_section")
             assert news_section is not None
-            assert news_section["subtitle"] is not None
+            assert news_section["subtitle"] == expected_news_subtitle
 
 
 class TestExtendedExpiration:

tests/unit/curated_recommendations/test_localization.py

@@ -1,7 +1,11 @@
 """Tests covering merino/curated_recommendations/localization.py"""
 
-from merino.curated_recommendations.localization import get_translation
+from datetime import datetime
+
+import pytest
+
 from merino.curated_recommendations.corpus_backends.protocol import ScheduledSurfaceId
+from merino.curated_recommendations.localization import get_translation, get_localized_date
 
 
 def test_get_translation_existing_translation():
@@ -28,3 +32,20 @@ def test_get_translation_non_existing_slug(caplog):
     errors = [r for r in caplog.records if r.levelname == "ERROR"]
     assert len(errors) == 1
     assert "Missing or empty translation for topic" in errors[0].message
+
+
+@pytest.mark.parametrize(
+    "surface_id, expected_output",
+    [
+        (ScheduledSurfaceId.NEW_TAB_EN_US, "December 17, 2024"),
+        (ScheduledSurfaceId.NEW_TAB_EN_GB, "17 December 2024"),
+        (ScheduledSurfaceId.NEW_TAB_DE_DE, "17. Dezember 2024"),
+        (ScheduledSurfaceId.NEW_TAB_FR_FR, "17 décembre 2024"),
+        (ScheduledSurfaceId.NEW_TAB_ES_ES, "17 de diciembre de 2024"),
+        (ScheduledSurfaceId.NEW_TAB_IT_IT, "17 dicembre 2024"),
+        (ScheduledSurfaceId.NEW_TAB_EN_INTL, "17 December 2024"),
+    ],
+)
+def test_get_localized_date_output(surface_id: ScheduledSurfaceId, expected_output: str):
+    """Test that get_localized_date returns correctly formatted date strings."""
+    assert get_localized_date(surface_id, date=datetime(2024, 12, 17)) == expected_output