fix(sync): dashboard sync covers current year plus Nov-Dec of previous

/sync-bank now uses one shared default window in both implementations:
1 November of the previous year to 31 December of the current year.
Payments dated around New Year are picked up in January; duplicates
are still filtered by Sync ID.

Python used a hardcoded 2026 window and would have stopped syncing on
2027-01-01; Go used the current calendar year only.

Adds make sync-year [YEAR=N] with the same window. The CLI default
without flags (last 30 days) is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 2026-10-08 12:04 CEST — fix(sync): dashboard sync covers the current year plus Nov–Dec of the previous one
+
+- `/sync-bank` now uses one shared default window in both implementations: 1 November of the previous year to 31 December of the current year. Payments dated around New Year are picked up in January; duplicates are still filtered by Sync ID.
+- Python previously used a hardcoded `2026-01-01`..`2026-12-31` and would have stopped syncing on 2027-01-01; Go used the current calendar year only.
+- Added `make sync-year [YEAR=N]` with the same window; `make sync-2026` is kept. The CLI default without flags (last 30 days) is unchanged.
+- Key files: `go/internal/services/banksync/sync.go` (`DefaultWindow`), `go/cmd/fuj/main.go`, `legacy/scripts/sync_fio_to_sheets.py` (`default_sync_window`), `legacy/app.py`.
+
 ## 2026-10-08 11:53 CEST — feat(fees): adult rates for 2026-07 through 2026-12, default 600
 
 - Adult default monthly rate (months not in the table): 700 → 600 CZK.

CLAUDE.md

@@ -64,7 +64,7 @@ make web-debug    # Same with FLASK_DEBUG=1
 make test         # Run all tests (unittest discover)
 make test-v       # Tests with verbose output
 make fees         # Print fee report from attendance sheet
-make sync-2026    # Sync Fio bank transactions for 2026 to Google Sheets
+make sync-year    # Sync Fio transactions for the current year plus Nov-Dec of the previous one (YEAR=N to override)
 make infer        # Auto-fill Person/Purpose/Amount columns in payments sheet
 make reconcile    # Print balance report from Google Sheets data
 make image        # Build the legacy Python Docker image

Makefile

@@ -1,4 +1,4 @@
-.PHONY: help fees match web web-py web-debug web-go go-build go-test go-test-all go-parity go-run go-sync-debug go-lint capture-fixtures parity image run sync sync-2026 test test-v docs
+.PHONY: help fees match web web-py web-debug web-go go-build go-test go-test-all go-parity go-run go-sync-debug go-lint capture-fixtures parity image run sync sync-2026 sync-year test test-v docs
 
 # Legacy Python implementation lives in legacy/ (Go in go/ is primary).
 LEGACY := legacy
@@ -39,6 +39,7 @@ help:
 	@echo "  make sync        - Sync Fio transactions to Google Sheets"
 	@echo "  make sync-2025   - Sync Fio transactions for Q4 2025 (Oct-Dec)"
 	@echo "  make sync-2026   - Sync Fio transactions for the whole year of 2026"
+	@echo "  make sync-year [YEAR=N] - Sync Fio transactions for YEAR plus Nov-Dec of the year before (default: current year)"
 	@echo "  make sync-debug [DAYS=N] - Dry-run Python sync with Fio diagnostics and txn table (default DAYS=30)"
 	@echo "  make infer       - Infer payment details (Person, Purpose, Amount) in the sheet"
 	@echo "  make reconcile   - Show balance report using Google Sheets data"
@@ -130,6 +131,10 @@ sync-2025: $(PYTHON)
 sync-2026: $(PYTHON)
 	$(PYTHON) $(LEGACY)/scripts/sync_fio_to_sheets.py --credentials $(CREDENTIALS) --from 2026-01-01 --to 2026-12-31 --sort-by-date
 
+YEAR ?= $(shell date +%Y)
+sync-year: $(PYTHON)
+	$(PYTHON) $(LEGACY)/scripts/sync_fio_to_sheets.py --credentials $(CREDENTIALS) --from $(shell expr $(YEAR) - 1)-11-01 --to $(YEAR)-12-31 --sort-by-date
+
 sync-debug: $(PYTHON)  ## Dry-run Python sync with Fio diagnostics and txn table (default DAYS=30)
 	$(PYTHON) $(LEGACY)/scripts/sync_fio_to_sheets.py --credentials $(CREDENTIALS) --days $(DAYS) --dry-run --print-fio-table
 

docs/plans/2026-10-08-1026-pre-feature-cleanup-tasks.md

@@ -50,7 +50,9 @@ before new feature work starts. Companion to the Go rewrite tracker,
   - September and October 2026 are billed at the defaults: 700 CZK adults,
     500 CZK juniors.
   - If those are not the intended rates, add the months in both files.
-- [ ] **T3** Remove the hardcoded 2026 window from Python `/sync-bank`
+- [x] **T3** Done 2026-10-08, extended: both dashboards now sync the
+  current year plus November–December of the previous one. Original task:
+  remove the hardcoded 2026 window from Python `/sync-bank`
   (`app.py`, the `sync_to_sheets` call with `2026-01-01` / `2026-12-31`).
   - It stops picking up transactions on 2027-01-01. Go already uses the
     current year.

go/cmd/fuj/main.go

@@ -92,9 +92,7 @@ func serverCmd(args []string) {
 
 	actions := web.ActionHandlers{
 		BankSync: func(ctx context.Context, out io.Writer) error {
-			yr := time.Now().Year()
+			from, to := banksync.DefaultWindow(time.Now())
-			from := time.Date(yr, 1, 1, 0, 0, 0, 0, time.UTC)
-			to := time.Date(yr, 12, 31, 23, 59, 59, 0, time.UTC)
 
 			fmt.Fprintln(out, "=== Sync Fio Transactions ===")
 			n, err := banksync.SyncToSheets(ctx, config.PaymentsSheetID, fioClients, sheetsCli,

go/internal/services/banksync/sync.go

@@ -36,6 +36,18 @@ type SyncOpts struct {
 	PrintFioTable bool      // with DryRun: print every fetched Fio txn with NEW/DUP status
 }
 
+// DefaultWindow is the window used by the dashboard sync: the whole current
+// calendar year plus the last two months of the previous one, so payments
+// dated around New Year are still picked up in January. Re-fetching is safe
+// because rows are deduplicated by Sync ID.
+// Mirrors default_sync_window in legacy/scripts/sync_fio_to_sheets.py.
+func DefaultWindow(now time.Time) (from, to time.Time) {
+	yr := now.Year()
+	from = time.Date(yr-1, time.November, 1, 0, 0, 0, 0, time.UTC)
+	to = time.Date(yr, time.December, 31, 23, 59, 59, 0, time.UTC)
+	return from, to
+}
+
 // SyncToSheets fetches Fio transactions from all provided clients and appends
 // new ones to the payments sheet. Returns the number of rows appended.
 // Ports legacy/scripts/sync_fio_to_sheets.py sync_to_sheets.

go/internal/services/banksync/sync_test.go

@@ -193,3 +193,23 @@ func syncIDFor(tx fio.Transaction) string {
 		Sender: tx.Sender, VS: tx.VS, Message: tx.Message, BankID: tx.BankID,
 	})
 }
+
+func TestDefaultWindow(t *testing.T) {
+	cases := []struct {
+		now      time.Time
+		from, to string
+	}{
+		{time.Date(2026, 10, 8, 12, 0, 0, 0, time.UTC), "2025-11-01", "2026-12-31"},
+		{time.Date(2027, 1, 1, 0, 0, 0, 0, time.UTC), "2026-11-01", "2027-12-31"},
+		{time.Date(2027, 12, 31, 23, 0, 0, 0, time.UTC), "2026-11-01", "2027-12-31"},
+	}
+	for _, tc := range cases {
+		from, to := DefaultWindow(tc.now)
+		if got := from.Format("2006-01-02"); got != tc.from {
+			t.Errorf("DefaultWindow(%s) from: want %s, got %s", tc.now.Format("2006-01-02"), tc.from, got)
+		}
+		if got := to.Format("2006-01-02"); got != tc.to {
+			t.Errorf("DefaultWindow(%s) to: want %s, got %s", tc.now.Format("2006-01-02"), tc.to, got)
+		}
+	}
+}

legacy/app.py

@@ -30,7 +30,7 @@ from views import (
     adapt_junior_members,
 )
 from cache_utils import get_sheet_modified_time, read_cache, write_cache, _LAST_CHECKED, flush_cache
-from sync_fio_to_sheets import sync_to_sheets
+from sync_fio_to_sheets import sync_to_sheets, default_sync_window
 from infer_payments import infer_payments
 
 def get_cached_data(cache_key, sheet_id, fetch_func, *args, serialize=None, deserialize=None, **kwargs):
@@ -128,13 +128,14 @@ def sync_bank():
     success = True
     try:
         with contextlib.redirect_stdout(output), contextlib.redirect_stderr(output):
-            # sync_to_sheets: equivalent of make sync-2026
+            # sync_to_sheets: equivalent of make sync-year (same default window as Go)
-            output.write("=== Syncing Fio transactions (2026) ===\n")
+            date_from, date_to = default_sync_window()
+            output.write(f"=== Syncing Fio transactions ({date_from} to {date_to}) ===\n")
             sync_to_sheets(
                 spreadsheet_id=PAYMENTS_SHEET_ID,
                 credentials_path=CREDENTIALS_PATH,
-                date_from_str="2026-01-01",
+                date_from_str=date_from,
-                date_to_str="2026-12-31",
+                date_to_str=date_to,
                 sort_by_date=True,
             )
             output.write("\n=== Inferring payment details ===\n")

legacy/scripts/sync_fio_to_sheets.py

@@ -59,6 +59,18 @@ def get_sheets_service(credentials_path: str):
     return _SHEETS_SERVICE
 
 
+def default_sync_window(today=None) -> tuple[str, str]:
+    """Window used by the dashboard sync, as (from, to) in YYYY-MM-DD.
+
+    The whole current calendar year plus the last two months of the previous
+    one, so payments dated around New Year are still picked up in January.
+    Re-fetching is safe because rows are deduplicated by Sync ID.
+    Mirrors DefaultWindow in go/internal/services/banksync/sync.go.
+    """
+    year = (today or datetime.now()).year
+    return f"{year - 1}-11-01", f"{year}-12-31"
+
+
 def as_text_cell(value) -> str:
     """Mark a value to be stored as text when written with USER_ENTERED.
 

legacy/tests/test_app.py

@@ -23,6 +23,20 @@ class TestWebApp(unittest.TestCase):
         app.config['TESTING'] = True
         self.client = app.test_client()
 
+    @patch('app.flush_cache', return_value=0)
+    @patch('app.infer_payments')
+    @patch('app.sync_to_sheets')
+    def test_sync_bank_uses_default_window(self, mock_sync, mock_infer, mock_flush):
+        """/sync-bank syncs the current year plus Nov-Dec of the previous one, not a hardcoded year."""
+        from datetime import datetime
+        year = datetime.now().year
+        response = self.client.get('/sync-bank')
+        self.assertEqual(response.status_code, 200)
+        kwargs = mock_sync.call_args.kwargs
+        self.assertEqual(kwargs['date_from_str'], f"{year - 1}-11-01")
+        self.assertEqual(kwargs['date_to_str'], f"{year}-12-31")
+        mock_infer.assert_called_once()
+
     def test_index_page(self):
         """Test that / returns the refresh meta tag"""
         response = self.client.get('/')

legacy/tests/test_sync_fio.py

@@ -1,9 +1,17 @@
 import contextlib
 import io
 import unittest
+from datetime import datetime
 from unittest.mock import MagicMock, patch
 
-from scripts.sync_fio_to_sheets import COLUMN_LABELS, as_text_cell, sync_to_sheets
+from scripts.sync_fio_to_sheets import COLUMN_LABELS, as_text_cell, default_sync_window, sync_to_sheets
+
+
+class TestDefaultSyncWindow(unittest.TestCase):
+    def test_current_year_plus_last_two_months_of_previous(self):
+        self.assertEqual(default_sync_window(datetime(2026, 10, 8)), ("2025-11-01", "2026-12-31"))
+        self.assertEqual(default_sync_window(datetime(2027, 1, 1)), ("2026-11-01", "2027-12-31"))
+        self.assertEqual(default_sync_window(datetime(2027, 12, 31)), ("2026-11-01", "2027-12-31"))
 
 
 class TestAsTextCell(unittest.TestCase):