fix: Convert Daily Schedule Time to UTC (#3914)

docs/docs/documentation/getting-started/installation/backend-config.md

@@ -5,19 +5,19 @@
 ### General
 
 | Variables                     |        Default        | Description                                                                                               |
-| ----------------------------- | :-------------------: | ----------------------------------------------------------------------------------- |
+| ----------------------------- | :-------------------: | --------------------------------------------------------------------------------------------------------- |
 | PUID                          |          911          | UserID permissions between host OS and container                                                          |
 | PGID                          |          911          | GroupID permissions between host OS and container                                                         |
 | DEFAULT_GROUP                 |         Home          | The default group for users                                                                               |
 | BASE_URL                      | http://localhost:8080 | Used for Notifications                                                                                    |
 | TOKEN_TIME                    |          48           | The time in hours that a login/auth token is valid                                                        |
 | API_PORT                      |         9000          | The port exposed by backend API. **Do not change this if you're running in Docker**                       |
-| API_DOCS                      |         True          | Turns on/off access to the API documentation locally.                               |
+| API_DOCS                      |         True          | Turns on/off access to the API documentation locally                                                      |
 | TZ                            |          UTC          | Must be set to get correct date/time on the server                                                        |
 | ALLOW_SIGNUP<super>\*</super> |         false         | Allow user sign-up without token                                                                          |
 | LOG_CONFIG_OVERRIDE           |                       | Override the config for logging with a custom path                                                        |
 | LOG_LEVEL                     |         info          | Logging level (e.g. critical, error, warning, info, debug, trace)                                         |
-| DAILY_SCHEDULE_TIME           |         23:45         | The time of day to run the daily tasks.                                             |
+| DAILY_SCHEDULE_TIME           |         23:45         | The time of day to run daily server tasks, in HH:MM format. Use the server's local time, *not* UTC        |
 
 <super>\*</super> Starting in v1.4.0 this was changed to default to `false` as part of a security review of the application.
 

mealie/core/settings/settings.py

@@ -1,6 +1,10 @@
+import logging
 import secrets
+from datetime import datetime, timezone
 from pathlib import Path
+from typing import NamedTuple
 
+from dateutil.tz import tzlocal
 from pydantic import field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
@@ -9,6 +13,11 @@ from mealie.core.settings.themes import Theme
 from .db_providers import AbstractDBProvider, db_provider_factory
 
 
+class ScheduleTime(NamedTuple):
+    hour: int
+    minute: int
+
+
 def determine_secrets(data_dir: Path, production: bool) -> str:
     if not production:
         return "shh-secret-test-key"
@@ -58,6 +67,44 @@ class AppSettings(BaseSettings):
     ALLOW_SIGNUP: bool = False
 
     DAILY_SCHEDULE_TIME: str = "23:45"
+    """Local server time, in HH:MM format. See `DAILY_SCHEDULE_TIME_UTC` for the parsed UTC equivalent"""
+
+    _logger: logging.Logger | None = None
+
+    @property
+    def logger(self) -> logging.Logger:
+        if self._logger is None:
+            # lazy load the logger, since get_logger depends on the settings being loaded
+            from mealie.core.root_logger import get_logger
+
+            self._logger = get_logger()
+
+        return self._logger
+
+    @property
+    def DAILY_SCHEDULE_TIME_UTC(self) -> ScheduleTime:
+        """The DAILY_SCHEDULE_TIME in UTC, parsed into hours and minutes"""
+
+        # parse DAILY_SCHEDULE_TIME into hours and minutes
+        try:
+            hour_str, minute_str = self.DAILY_SCHEDULE_TIME.split(":")
+            local_hour = int(hour_str)
+            local_minute = int(minute_str)
+        except ValueError:
+            local_hour = 23
+            local_minute = 45
+            self.logger.exception(
+                f"Unable to parse {self.DAILY_SCHEDULE_TIME=} as HH:MM; defaulting to {local_hour}:{local_minute}"
+            )
+
+        # DAILY_SCHEDULE_TIME is in local time, so we convert it to UTC
+        local_tz = tzlocal()
+        now = datetime.now(local_tz)
+        local_time = now.replace(hour=local_hour, minute=local_minute)
+        utc_time = local_time.astimezone(timezone.utc)
+
+        self.logger.debug(f"Local time: {local_hour}:{local_minute} | UTC time: {utc_time.hour}:{utc_time.minute}")
+        return ScheduleTime(utc_time.hour, utc_time.minute)
 
     # ===============================================
     # Security Configuration

mealie/services/scheduler/scheduler_service.py

@@ -29,20 +29,12 @@ class SchedulerService:
 
 async def schedule_daily():
     now = datetime.now(timezone.utc)
-    daily_schedule_time = get_app_settings().DAILY_SCHEDULE_TIME
-    logger.debug(
-        "Current time is %s and DAILY_SCHEDULE_TIME is %s",
-        str(now),
-        daily_schedule_time,
-    )
-    try:
-        hour_target, minute_target = _parse_daily_schedule_time(daily_schedule_time)
-    except Exception:
-        logger.exception(f"Unable to parse {daily_schedule_time=}")
-        hour_target = 23
-        minute_target = 45
+    daily_schedule_time = get_app_settings().DAILY_SCHEDULE_TIME_UTC
+    logger.debug(f"Current time is {now} and DAILY_SCHEDULE_TIME (in UTC) is {daily_schedule_time}")
 
-    next_schedule = now.replace(hour=hour_target, minute=minute_target, second=0, microsecond=0)
+    next_schedule = now.replace(
+        hour=daily_schedule_time.hour, minute=daily_schedule_time.minute, second=0, microsecond=0
+    )
     delta = next_schedule - now
     if delta < timedelta(0):
         next_schedule = next_schedule + timedelta(days=1)
@@ -61,12 +53,6 @@ async def schedule_daily():
     await run_daily()
 
 
-def _parse_daily_schedule_time(time):
-    hour_target = int(time.split(":")[0])
-    minute_target = int(time.split(":")[1])
-    return hour_target, minute_target
-
-
 def _scheduled_task_wrapper(callable):
     try:
         callable()