feat: improve attendance parsing logic and fix payment date formatting

scripts/match_payments.py

@@ -159,6 +159,27 @@ def infer_transaction_details(tx: dict, member_names: list[str]) -> dict:
     }
 
 
+def format_date(val) -> str:
+    """Normalize date from Google Sheet (handles serial numbers and strings)."""
+    if val is None or val == "":
+        return ""
+    
+    # Handle Google Sheets serial dates (number of days since 1899-12-30)
+    if isinstance(val, (int, float)):
+        base_date = datetime(1899, 12, 30)
+        dt = base_date + timedelta(days=val)
+        return dt.strftime("%Y-%m-%d")
+    
+    val_str = str(val).strip()
+    if not val_str:
+        return ""
+        
+    # If already YYYY-MM-DD, return as is
+    if len(val_str) == 10 and val_str[4] == "-" and val_str[7] == "-":
+        return val_str
+        
+    return val_str
+
 def fetch_sheet_data(spreadsheet_id: str, credentials_path: str) -> list[dict]:
     """Fetch all rows from the Google Sheet and convert to a list of dicts."""
     service = get_sheets_service(credentials_path)
@@ -197,7 +218,7 @@ def fetch_sheet_data(spreadsheet_id: str, credentials_path: str) -> list[dict]:
             return row[idx] if idx != -1 and idx < len(row) else ""
 
         tx = {
-            "date": get_val(idx_date),
+            "date": format_date(get_val(idx_date)),
             "amount": get_val(idx_amount),
             "manual_fix": get_val(idx_manual),
             "person": get_val(idx_person),