Show "1 day" not "1 days"

Closes: 25

web_view.py

@@ -2,10 +2,11 @@
 
 """Web page to show upcoming events."""
 
+import functools
 import inspect
 import sys
 import traceback
-from datetime import date, datetime, timezone
+from datetime import date, datetime
 
 import flask
 import werkzeug
@@ -44,22 +45,27 @@ def exception_handler(e: werkzeug.exceptions.InternalServerError) -> tuple[str,
     )
 
 
+def delta_days(today: date, when: date) -> str:
+    """Return number of days from today as a string."""
+    delta = (when - today).days
+
+    match delta:
+        case 0:
+            return "today"
+        case 1:
+            return "1 day"
+        case _:
+            return f"{delta:,d} days"
+
+
 @app.route("/")
 def index() -> str:
     """Index page."""
     now = datetime.now()
-    today = now.date()
     data = get_data(now)
-    now_utc = datetime.now(timezone.utc)
+    days = functools.partial(delta_days, now.date())
 
-    def days_hours(when: datetime) -> str:
-        delta = when - (now if when.tzinfo is None else now_utc)
-        return f"{delta.days:>5,d} days {delta.seconds // 3600:>2.0f} hours"
-
-    def days(when: date) -> str:
-        return "today" if when == today else f"{(when - today).days:,d} days"
-
-    return flask.render_template("index.html", days=days, days_hours=days_hours, **data)
+    return flask.render_template("index.html", days=days, **data)
 
 
 if __name__ == "__main__":