Add end of financial year: 5 April

Closes: #3

agenda/__init__.py

@@ -181,6 +181,22 @@ def next_economist(input_date: date) -> date:
     return next_thursday_date
 
 
+def uk_financial_year_end(input_date: date) -> date:
+    """Next date of the end of the UK financial year, April 5th."""
+    # Determine the year of the input date
+    year = input_date.year
+
+    # Calculate the UK financial year end date (April 5th)
+    uk_financial_year_end = date(year, 4, 5)
+
+    # If the input date is on or after the UK financial year end date,
+    # move to the next year
+    if input_date > uk_financial_year_end:
+        uk_financial_year_end = date(year + 1, 4, 5)
+
+    return uk_financial_year_end
+
+
 def timedelta_display(delta: timedelta) -> str:
     """Format timedelta as a human readable string."""
     total_seconds = int(delta.total_seconds())
@@ -259,6 +275,7 @@ def get_data() -> dict[str, str | object]:
         "us_clock_change": get_next_timezone_transition("America/New_York"),
         "mothers_day": next_uk_mothers_day(today),
         "fathers_day": next_uk_fathers_day(today),
+        "uk_financial_year_end": uk_financial_year_end(today),
     }
 
     return reply

templates/index.html

@@ -28,6 +28,10 @@
       {{days(fathers_day)}}
       {{fathers_day.strftime("%a, %d %b %Y")}}</li>
 
+    <li>End of financial year:
+      {{days(uk_financial_year_end)}}
+      {{uk_financial_year_end.strftime("%a, %d %b %Y")}}</li>
+
     <li>UK bank holiday:
       {{days(bank_holiday["date"])}}
       {{bank_holiday["date"].strftime("%a, %d %b")}}