fix: fix timezone handling across backend and frontend (v0.3.1)

- Add tz.py with local_strftime/to_local helpers that read system.timezone
  from DB and convert UTC datetimes to venue local time before formatting
- Fix all strftime() calls in orders.py, reports.py, printer_service.py
  that were formatting UTC datetimes without timezone conversion
- Fix get_order endpoint returning raw dicts without Z suffix on datetimes,
  causing JS new Date() to treat timestamps as local instead of UTC
- Fix fmtDate() in tokens.js that stripped the T separator before parsing,
  breaking UTC-to-local conversion for all report date displays
- Make open/partially_paid table chips more visually distinct on dashboard

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

local_backend/config.py

@@ -19,7 +19,7 @@ class Settings(BaseSettings):
     CLOUD_URL: str = ""
     SECRET_KEY: str = "change-me-generate-a-long-random-string"
     DATABASE_URL: str = f"sqlite:///{_DB_DEFAULT.as_posix()}"
-    VERSION: str = "0.0.0"
+    VERSION: str = "0.3.1"
     CONNECT_SYNC_INTERVAL_SECONDS: int = 30  # how often to poll for pending online orders
 
     model_config = {"env_file": str(_HERE / ".env"), "env_file_encoding": "utf-8"}

local_backend/routers/orders.py

@@ -1,6 +1,16 @@
 import json
 from datetime import datetime, timezone
 from fastapi import APIRouter, Depends, HTTPException, status, BackgroundTasks
+from tz import local_strftime
+
+
+def _iso(dt) -> str | None:
+    """Serialize a datetime to ISO 8601 with Z suffix so browsers parse it as UTC."""
+    if dt is None:
+        return None
+    if dt.tzinfo is None:
+        return dt.isoformat() + "Z"
+    return dt.isoformat()
 from sqlalchemy.orm import Session
 from typing import List, Optional
 
@@ -163,11 +173,11 @@ def get_order(order_id: int, db: Session = Depends(get_db), user: User = Depends
             "removed_ingredients": i.removed_ingredients,
             "notes": i.notes,
             "status": i.status,
-            "added_at": i.added_at,
+            "added_at": _iso(i.added_at),
             "printed": i.printed,
             "paid_by": i.paid_by,
             "paid_by_name": name_map.get(i.paid_by) if i.paid_by else None,
-            "paid_at": i.paid_at,
+            "paid_at": _iso(i.paid_at),
             "payment_method": i.payment_method,
             "paid_in_shift_id": i.paid_in_shift_id,
         }
@@ -183,8 +193,8 @@ def get_order(order_id: int, db: Session = Depends(get_db), user: User = Depends
             "amount": l.amount,
             "payment_method": l.payment_method,
             "note": l.note,
-            "created_at": l.created_at,
+            "created_at": _iso(l.created_at),
-            "offline_at": l.offline_at,
+            "offline_at": _iso(l.offline_at) if isinstance(l.offline_at, datetime) else l.offline_at,
             "is_duplicate": l.is_duplicate,
         }
 
@@ -205,9 +215,9 @@ def get_order(order_id: int, db: Session = Depends(get_db), user: User = Depends
         "table_id": order.table_id,
         "table_name": table_name,
         "opened_by": order.opened_by,
-        "opened_at": order.opened_at,
+        "opened_at": _iso(order.opened_at),
         "status": order.status,
-        "closed_at": order.closed_at,
+        "closed_at": _iso(order.closed_at),
         "closed_by": order.closed_by,
         "notes": order.notes,
         "business_day_id": order.business_day_id,
@@ -657,8 +667,8 @@ def print_order(
         "order_id": order.id,
         "table_name": table_name,
         "waiter_name": waiter_name,
-        "opened_at": order.opened_at.strftime("%d/%m/%Y %H:%M"),
+        "opened_at": local_strftime(order.opened_at, "%d/%m/%Y %H:%M"),
-        "closed_at": order.closed_at.strftime("%d/%m/%Y %H:%M") if order.closed_at else None,
+        "closed_at": local_strftime(order.closed_at, "%d/%m/%Y %H:%M") if order.closed_at else None,
         "status": order.status,
         "items": items_data,
         "total": grand_total,
@@ -953,7 +963,7 @@ def print_synopsis(
         "order_id": order.id,
         "table_name": table_name,
         "waiter_name": waiter_name,
-        "opened_at": order.opened_at.strftime("%d/%m/%Y %H:%M"),
+        "opened_at": local_strftime(order.opened_at, "%d/%m/%Y %H:%M"),
         "items": items_data,
         "total": total,
         "paid_total": paid_total,

local_backend/routers/reports.py

@@ -3,6 +3,7 @@ import io
 import json
 
 from fastapi import APIRouter, Depends, Query, HTTPException, BackgroundTasks
+from tz import local_strftime, to_local
 from fastapi.responses import StreamingResponse
 from pydantic import BaseModel
 from sqlalchemy.orm import Session
@@ -87,8 +88,8 @@ def shift_summary(
             order = db.query(Order).filter(Order.id == oid).first()
             summary[wid]["order_data"][oid] = {
                 "id": oid,
-                "time_open": order.opened_at.strftime("%H:%M") if order else "",
+                "time_open": local_strftime(order.opened_at, "%H:%M") if order else "",
-                "time_close": order.closed_at.strftime("%H:%M") if order and order.closed_at else "",
+                "time_close": local_strftime(order.closed_at, "%H:%M") if order and order.closed_at else "",
                 "table": tables_db.get(order.table_id, f"#{oid}") if order else f"#{oid}",
                 "total": 0.0,
                 "items": [],
@@ -160,8 +161,8 @@ def shift_orders_summary(
             order = db.query(Order).filter(Order.id == oid).first()
             summary[wid]["order_data"][oid] = {
                 "id": oid,
-                "time_open": order.opened_at.strftime("%H:%M") if order else "",
+                "time_open": local_strftime(order.opened_at, "%H:%M") if order else "",
-                "time_close": order.closed_at.strftime("%H:%M") if order and order.closed_at else "",
+                "time_close": local_strftime(order.closed_at, "%H:%M") if order and order.closed_at else "",
                 "table": tables_db.get(order.table_id, f"#{oid}") if order else f"#{oid}",
                 "total": 0.0,
                 "items": [],
@@ -382,7 +383,7 @@ def printer_totals(
             order = db.query(Order).filter(Order.id == oid).first()
             order_map[pid][oid] = {
                 "order_id": oid,
-                "time": log.printed_at.strftime("%H:%M"),
+                "time": local_strftime(log.printed_at, "%H:%M"),
                 "table": tables_db.get(order.table_id, f"#{oid}") if order else f"#{oid}",
                 "total": 0.0,
                 "items": [],
@@ -452,7 +453,7 @@ def _build_printer_block(printer_id: int, printer_name: str, logs, tables, db, m
             if order:
                 order_map[oid] = {
                     "id": oid,
-                    "time": log.printed_at.strftime("%H:%M"),
+                    "time": local_strftime(log.printed_at, "%H:%M"),
                     "table": tables.get(order.table_id, f"#{order.table_id}"),
                     "total": 0.0,
                     "items": [],
@@ -535,8 +536,8 @@ def print_waiter(
         total = sum(i.unit_price * i.quantity for i in active_items)
         order_data.append({
             "id": o.id,
-            "time_open": o.opened_at.strftime("%H:%M"),
+            "time_open": local_strftime(o.opened_at, "%H:%M"),
-            "time_close": o.closed_at.strftime("%H:%M") if o.closed_at else "",
+            "time_close": local_strftime(o.closed_at, "%H:%M") if o.closed_at else "",
             "table": tables.get(o.table_id, f"#{o.table_id}"),
             "total": total,
             "items": [
@@ -556,8 +557,8 @@ def print_waiter(
         "items": items_count,
         "total": grand_total,
         "order_data": order_data if body.mode == "extensive" else [],
-        "from_dt": from_dt.strftime("%d/%m/%Y %H:%M"),
+        "from_dt": local_strftime(from_dt, "%d/%m/%Y %H:%M"),
-        "to_dt": to_dt.strftime("%d/%m/%Y %H:%M"),
+        "to_dt": local_strftime(to_dt, "%d/%m/%Y %H:%M"),
     }
 
     background_tasks.add_task(print_waiter_report, printer.ip_address, printer.port, report, body.mode)
@@ -592,13 +593,13 @@ def print_printer_totals(
     # Determine period label for the receipt header
     if body.business_day_id:
         bd = db.query(BusinessDay).filter(BusinessDay.id == body.business_day_id).first()
-        period_label = bd.opened_at.strftime("%d/%m/%Y") if bd else f"Workday #{body.business_day_id}"
+        period_label = local_strftime(bd.opened_at, "%d/%m/%Y") if bd else f"Workday #{body.business_day_id}"
         period_is_workday = True
     else:
         from_dt = datetime.fromisoformat(body.from_dt) if body.from_dt else None
         to_dt = datetime.fromisoformat(body.to_dt) if body.to_dt else None
         period_label = (
-            f"{from_dt.strftime('%d/%m/%Y')} - {to_dt.strftime('%d/%m/%Y')}"
+            f"{local_strftime(from_dt, '%d/%m/%Y')} - {local_strftime(to_dt, '%d/%m/%Y')}"
             if from_dt and to_dt else "—"
         )
         period_is_workday = False
@@ -649,12 +650,12 @@ def _analytics_period(body: PrintAnalyticsBody, db) -> tuple[str, bool]:
     """Return (period_label, period_is_workday)."""
     if body.business_day_id:
         bd = db.query(BusinessDay).filter(BusinessDay.id == body.business_day_id).first()
-        label = bd.opened_at.strftime("%d/%m/%Y") if bd else f"Workday #{body.business_day_id}"
+        label = local_strftime(bd.opened_at, "%d/%m/%Y") if bd else f"Workday #{body.business_day_id}"
         return label, True
     from_dt = datetime.fromisoformat(body.from_dt) if body.from_dt else None
     to_dt = datetime.fromisoformat(body.to_dt) if body.to_dt else None
     label = (
-        f"{from_dt.strftime('%d/%m/%Y')} - {to_dt.strftime('%d/%m/%Y')}"
+        f"{local_strftime(from_dt, '%d/%m/%Y')} - {local_strftime(to_dt, '%d/%m/%Y')}"
         if from_dt and to_dt else "—"
     )
     return label, False
@@ -1253,7 +1254,7 @@ def revenue_trends(
 
     buckets: dict = {}
     for order in orders:
-        dt = order.opened_at
+        dt = to_local(order.opened_at)
         if granularity == "monthly":
             key = dt.strftime("%Y-%m")
         elif granularity == "weekly":

local_backend/services/printer_service.py

@@ -18,6 +18,7 @@ from sqlalchemy.orm import Session
 
 from database import SessionLocal
 from models.order import Order, OrderItem, PrintLog
+from tz import to_local
 from models.printer import Printer
 from models.product import Product
 from models.settings import PosSettings
@@ -232,8 +233,8 @@ def _print_line(p: Network, text: str, size: int, bold: bool, caps: bool,
 
 
 def _greek_date(dt: datetime.datetime) -> str:
-    """Return date/time string in Greek format: HH:MM DD-MM-YYYY"""
+    """Return date/time string in Greek format: HH:MM DD-MM-YYYY, converted to venue local time."""
-    return dt.strftime("%H:%M  %d-%m-%Y")
+    return to_local(dt).strftime("%H:%M  %d-%m-%Y")
 
 
 def check_printer(ip: str, port: int) -> bool:
@@ -282,7 +283,7 @@ def send_test_print(ip: str, port: int, name: str) -> Tuple[bool, str]:
         p._raw(b'\x1b\x21\x30')
         _raw_text(p, f"TEST — {name}\n")
         p._raw(b'\x1b\x21\x00')
-        now = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+        now = to_local(datetime.datetime.now(datetime.timezone.utc)).strftime("%Y-%m-%d %H:%M:%S")
         _raw_text(p, f"{now}\n")
         p._raw(b'\n\n\n')
         p.cut()
@@ -499,7 +500,7 @@ def _print_kitchen_ticket(p: Network, order: Order, items: List[OrderItem], db:
     # Resolve display names
     table_name  = order.table.label or str(order.table.number) if order.table else str(order.table_id)
     waiter_nick = (order.opener.nickname or order.opener.username) if order.opener else str(order.opened_by)
-    now_str     = _greek_date(datetime.datetime.now())
+    now_str     = _greek_date(datetime.datetime.now(datetime.timezone.utc))
 
     # ── COMPACT header — single line ────────────────────────────────────────
     if compact:

local_backend/tz.py

@@ -0,0 +1,39 @@
+"""Timezone utilities for converting UTC datetimes to the venue's local time."""
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
+from datetime import datetime, timezone
+
+from database import SessionLocal
+from models.settings import PosSettings
+
+_FALLBACK = "Europe/Athens"
+
+
+def _get_tz_name() -> str:
+    db = SessionLocal()
+    try:
+        row = db.query(PosSettings).filter(PosSettings.key == "system.timezone").first()
+        return row.value if row and row.value else _FALLBACK
+    except Exception:
+        return _FALLBACK
+    finally:
+        db.close()
+
+
+def to_local(dt: datetime) -> datetime:
+    """Convert a UTC-aware datetime to the venue's configured local timezone."""
+    if dt is None:
+        return dt
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    try:
+        tz = ZoneInfo(_get_tz_name())
+    except ZoneInfoNotFoundError:
+        tz = ZoneInfo(_FALLBACK)
+    return dt.astimezone(tz)
+
+
+def local_strftime(dt: datetime, fmt: str) -> str:
+    """Format a UTC-aware datetime in local time using the venue's timezone."""
+    if dt is None:
+        return "—"
+    return to_local(dt).strftime(fmt)

manager_dashboard/src/pages/DashboardPage.jsx

@@ -65,8 +65,8 @@ function Avatar({ name, avatarUrl, size = 36 }) {
 // ─── Table color tokens ────────────────────────────────────────────────────────
 
 const TABLE_COLORS = {
-  open:           { bg: '#eef7f0', border: '#d7ecdc', dot: '#2f9e5e', text: '#1f7042', label: 'Ανοιχτό' },
+  open:           { bg: '#bbf7d0', border: '#4ade80', dot: '#16a34a', text: '#14532d', label: 'Ανοιχτό' },
-  partially_paid: { bg: '#f4eefb', border: '#e3d4f3', dot: '#7a44c9', text: '#57309a', label: 'Μερική πληρ.' },
+  partially_paid: { bg: '#e9d5ff', border: '#a855f7', dot: '#7c3aed', text: '#4c1d95', label: 'Μερική πληρ.' },
   free:           { bg: '#f4f4f2', border: '#dfe2e6', dot: '#8a9099', text: '#5a6169', label: 'Ελεύθερο' },
 }
 

manager_dashboard/src/ui/tokens.js

@@ -94,13 +94,9 @@ export const fmtTime = (iso) => {
 }
 export const fmtDate = (iso) => {
   if (!iso) return '—'
-  // Parse as local time by replacing the T separator so Date treats it as local
+  const d = new Date(iso)
-  const d = new Date(String(iso).replace('T', ' '))
   if (isNaN(d)) return String(iso)
-  const day = String(d.getDate()).padStart(2, '0')
+  return d.toLocaleDateString('en-GB', { day: '2-digit', month: '2-digit', year: 'numeric' })
-  const month = String(d.getMonth() + 1).padStart(2, '0')
-  const year = d.getFullYear()
-  return `${day}/${month}/${year}`
 }
 
 // Format a raw YYYY-MM-DD string (from a date picker) as DD/MM/YYYY without any timezone conversion