diff --git a/classes/callbacks.py b/classes/callbacks.py
index 0093c9b..4b111be 100644
--- a/classes/callbacks.py
+++ b/classes/callbacks.py
@@ -10,7 +10,7 @@ class CallbackLanguage:
     language: str
 
     @classmethod
-    def from_callback(cls, callback: CallbackQuery):
+    def from_callback(cls, callback: CallbackQuery) -> "CallbackLanguage":
         """Parse callback query and extract language data from it.
 
         ### Args:
diff --git a/classes/garbage_entry.py b/classes/garbage_entry.py
index 7c97b60..644c305 100644
--- a/classes/garbage_entry.py
+++ b/classes/garbage_entry.py
@@ -23,7 +23,7 @@ class GarbageEntry:
     date: datetime
 
     @classmethod
-    async def from_dict(cls, data: Mapping[str, Any]):
+    async def from_dict(cls, data: Mapping[str, Any]) -> "GarbageEntry":
         """Generate GarbageEntry object from the mapping provided
 
         ### Args:
@@ -60,7 +60,7 @@ class GarbageEntry:
         )
 
     @classmethod
-    async def from_record(cls, data: Mapping[str, Any]):
+    async def from_record(cls, data: Mapping[str, Any]) -> "GarbageEntry":
         locations = [
             await Location.get(location_id) for location_id in data["locations"]
         ]
diff --git a/classes/location.py b/classes/location.py
index 5a29557..57497a3 100644
--- a/classes/location.py
+++ b/classes/location.py
@@ -28,7 +28,7 @@ class Location:
     timezone: Union[BaseTzInfo, DstTzInfo]
 
     @classmethod
-    async def get(cls, id: int):
+    async def get(cls, id: int) -> "Location":
         db_entry = await col_locations.find_one({"id": id})
 
         if db_entry is None:
@@ -40,7 +40,7 @@ class Location:
         return cls(**db_entry)
 
     @classmethod
-    async def find(cls, name: str):
+    async def find(cls, name: str) -> "Location":
         db_entry = await col_locations.find_one({"name": {"$regex": name}})
 
         if db_entry is None:
@@ -52,7 +52,7 @@ class Location:
         return cls(**db_entry)
 
     @classmethod
-    async def nearby(cls, lat: float, lon: float):
+    async def nearby(cls, lat: float, lon: float) -> "Location":
         db_entry = await col_locations.find_one({"location": {"$near": [lon, lat]}})
 
         if db_entry is None:
diff --git a/classes/pyrouser.py b/classes/pyrouser.py
index abb4a50..2a91a8a 100644
--- a/classes/pyrouser.py
+++ b/classes/pyrouser.py
@@ -1,7 +1,9 @@
 import logging
 from dataclasses import dataclass
-from typing import Any, Union
+from datetime import datetime, timedelta
+from typing import Any, Mapping, Tuple, Union
 
+import pytz
 from bson import ObjectId
 
 from classes.location import Location
@@ -42,9 +44,9 @@ class PyroUser:
         enabled: bool = True,
         location_id: int = 0,
         offset: int = 1,
-        time_hour: int = 18,
+        time_hour: int = 16,
         time_minute: int = 0,
-    ):
+    ) -> "PyroUser":
         db_entry = await col_users.find_one({"id": id})
 
         if db_entry is None:
@@ -72,7 +74,7 @@ class PyroUser:
         return cls(**db_entry)
 
     @classmethod
-    async def from_dict(cls, **kwargs):
+    async def from_dict(cls, **kwargs) -> "PyroUser":
         if "location" in kwargs:
             try:
                 kwargs["location"] = await Location.get(kwargs["location"])  # type: ignore
@@ -80,40 +82,85 @@ class PyroUser:
                 kwargs["location"] = None  # type: ignore
         return cls(**kwargs)
 
-    async def update_locale(self, locale: Union[str, None]) -> None:
+    async def update_locale(self, locale: Union[str, None]) -> Union[str, None]:
         """Change user's locale stored in the database.
 
         ### Args:
             * locale (`Union[str, None]`): New locale to be set.
         """
+
         logger.debug("%s's locale has been set to %s", self.id, locale)
+
         await col_users.update_one({"_id": self._id}, {"$set": {"locale": locale}})
 
-    async def update_state(self, enabled: bool = False) -> None:
+        self.locale = locale
+
+        return self.locale
+
+    async def update_state(self, enabled: bool = False) -> bool:
         logger.debug("%s's state has been set to %s", self.id, enabled)
+
         await col_users.update_one({"_id": self._id}, {"$set": {"enabled": enabled}})
 
-    async def update_location(self, location_id: int = 0) -> None:
+        self.enabled = enabled
+
+        return self.enabled
+
+    async def update_location(self, location_id: int = 0) -> Location:
         logger.debug("%s's location has been set to %s", self.id, location_id)
+
         await col_users.update_one(
             {"_id": self._id}, {"$set": {"location": location_id}}
         )
 
-    async def update_offset(self, offset: int = 1) -> None:
+        location = await Location.get(location_id)
+
+        # Execute if timezones of old and new locations are different
+        if self.location and (self.location.timezone.zone != location.timezone.zone):
+            # Get UTC time for selected reminder time
+            now_utc = datetime.now(pytz.utc).replace(
+                hour=self.time_hour, minute=self.time_minute, second=0, microsecond=0
+            )
+
+            # Get the time for the reminder time of old and new location
+            local_old = now_utc.astimezone(self.location.timezone)
+            local_new = (
+                location.timezone.localize(local_old.replace(tzinfo=None))
+            ).astimezone(pytz.utc)
+
+            # Update the time to match the new timezone
+            await self.update_time(hour=local_new.hour, minute=local_new.minute)
+
+        self.location = location
+
+        return self.location
+
+    async def update_offset(self, offset: int = 1) -> int:
         logger.debug("%s's offset has been set to %s", self.id, offset)
+
         await col_users.update_one({"_id": self._id}, {"$set": {"offset": offset}})
 
-    async def update_time(self, hour: int = 18, minute: int = 0) -> None:
+        self.offset = offset
+
+        return offset
+
+    async def update_time(self, hour: int = 16, minute: int = 0) -> Tuple[int, int]:
         logger.debug("%s's time has been set to %s h. %s m.", self.id, hour, minute)
+
         await col_users.update_one(
             {"_id": self._id}, {"$set": {"time_hour": hour, "time_minute": minute}}
         )
 
+        self.time_hour = hour
+        self.time_minute = minute
+
+        return self.time_hour, self.time_minute
+
     async def delete(self) -> None:
         logger.debug("%s's data has been deleted", self.id)
         await col_users.delete_one({"_id": self._id})
 
-    async def checkout(self) -> Any:
+    async def checkout(self) -> Mapping[str, Any]:
         logger.debug("%s's data has been checked out", self.id)
         db_entry = await col_users.find_one({"_id": self._id})
 
@@ -125,3 +172,60 @@ class PyroUser:
         del db_entry["_id"]  # type: ignore
 
         return db_entry
+
+    def get_reminder_date(self) -> datetime:
+        """Get next reminder date (year, month and day)
+
+        ### Raises:
+            * `AttributeError`: Some attribute(s) are missing
+
+        ### Returns:
+            * `datetime`: Datetime object of the next reminder date
+        """
+        if self.location is None:
+            logger.warning(
+                "Could not get the reminder date for %s: User does not have some attribute(s) set",
+                self.id,
+            )
+            raise AttributeError(
+                f"Could not get the reminder date for {self.id}: User does not have some attribute(s) set"
+            )
+
+        if not self.location.timezone:
+            logger.warning("Location %s does not have a timezone set", self.location.id)
+
+        return (
+            datetime.now(self.location.timezone or pytz.utc) + timedelta(days=1)
+        ).replace(hour=0, minute=0, second=0, microsecond=0)
+
+    def get_reminder_time(self) -> datetime:
+        """Get reminder time (hour and minute)
+
+        ### Raises:
+            * `AttributeError`: Some attribute(s) are missing
+
+        ### Returns:
+            * `datetime`: Datetime object of the next reminder date
+        """
+        if self.time_hour is None or self.time_minute is None or self.location is None:
+            logger.warning(
+                "Could not get the reminder time for %s: User does not have some attribute(s) set",
+                self.id,
+            )
+            raise AttributeError(
+                f"Could not get the reminder time for {self.id}: User does not have some attribute(s) set"
+            )
+
+        if not self.location.timezone:
+            logger.warning("Location %s does not have a timezone set", self.location.id)
+
+        return (
+            datetime.now(pytz.utc)
+            .replace(
+                hour=self.time_hour,
+                minute=self.time_minute,
+                second=0,
+                microsecond=0,
+            )
+            .astimezone(self.location.timezone or pytz.utc)
+        )
diff --git a/modules/reminder.py b/modules/reminder.py
index e2151e0..aca992d 100644
--- a/modules/reminder.py
+++ b/modules/reminder.py
@@ -1,6 +1,7 @@
 import logging
-from datetime import datetime, timedelta
+from datetime import datetime
 
+import pytz
 from bson import json_util
 from libbot.pyrogram.classes import PyroClient
 
@@ -9,13 +10,12 @@ from classes.location import Location
 from classes.pyrouser import PyroUser
 from modules.database import col_users
 from modules.database_api import col_entries
-from modules.utils import from_utc
 
 logger = logging.getLogger(__name__)
 
 
 async def remind(app: PyroClient) -> None:
-    utcnow = datetime.utcnow()
+    utcnow = datetime.now(pytz.utc)
 
     logger.debug("Performing reminder lookup for %s (UTCNOW)", utcnow)
 
@@ -40,12 +40,10 @@ async def remind(app: PyroClient) -> None:
         try:
             location: Location = await app.get_location(user.location.id)  # type: ignore
         except ValueError:
+            logger.warning("Skipping reminder for %s due to invalid location", user.id)
             continue
 
-        user_date = from_utc(
-            datetime.utcnow() + timedelta(days=user.offset),
-            user.location.timezone.zone,
-        ).replace(hour=0, minute=0, second=0, microsecond=0)
+        user_date = user.get_reminder_date().replace(tzinfo=None)
 
         entries = await col_entries.find(
             {
diff --git a/modules/utils.py b/modules/utils.py
index aaece4b..19b0586 100644
--- a/modules/utils.py
+++ b/modules/utils.py
@@ -1,12 +1,13 @@
 from datetime import datetime
 from typing import Union
 
-from pytz import UTC
-from pytz import timezone as pytz_timezone
+import pytz
 
 
 def to_utc(date: datetime, timezone: Union[str, None] = None) -> datetime:
-    """Move timezone unaware datetime object to UTC timezone and return it.
+    """*DEPRECATED AND WILL BE REMOVED IN FUTURE RELEASES*
+
+    Move timezone unaware datetime object to UTC timezone and return it.
 
     ### Args:
         * date (`datetime`): Datetime to be converted.
@@ -16,11 +17,15 @@ def to_utc(date: datetime, timezone: Union[str, None] = None) -> datetime:
         * `datetime`: Timezone unaware datetime in UTC with timezone's offset applied to it.
     """
     timezone = "UTC" if timezone is None else timezone
-    return pytz_timezone(timezone).localize(date).astimezone(UTC).replace(tzinfo=None)
+    return (
+        pytz.timezone(timezone).localize(date).astimezone(pytz.utc).replace(tzinfo=None)
+    )
 
 
 def from_utc(date: datetime, timezone: Union[str, None] = None) -> datetime:
-    """Move timezone unaware datetime object to the timezone specified and return it.
+    """*DEPRECATED AND WILL BE REMOVED IN FUTURE RELEASES*
+
+    Move timezone unaware datetime object to the timezone specified and return it.
 
     ### Args:
         * date (`datetime`): Datetime to be converted.
@@ -31,8 +36,5 @@ def from_utc(date: datetime, timezone: Union[str, None] = None) -> datetime:
     """
     timezone = "UTC" if timezone is None else timezone
     return (
-        pytz_timezone("UTC")
-        .localize(date)
-        .astimezone(pytz_timezone(timezone))
-        .replace(tzinfo=None)
+        pytz.utc.localize(date).astimezone(pytz.timezone(timezone)).replace(tzinfo=None)
     )
diff --git a/plugins/commands/set_offset.py b/plugins/commands/set_offset.py
index 30fce12..4fd2557 100644
--- a/plugins/commands/set_offset.py
+++ b/plugins/commands/set_offset.py
@@ -1,13 +1,13 @@
 import logging
 from datetime import datetime
 
+import pytz
 from convopyro import listen_message
 from pyrogram import filters
 from pyrogram.types import ForceReply, Message, ReplyKeyboardRemove
 
 from classes.pyroclient import PyroClient
 from modules import custom_filters
-from modules.utils import from_utc
 
 logger = logging.getLogger(__name__)
 
@@ -65,18 +65,19 @@ async def command_set_offset(app: PyroClient, message: Message):
 
     logger.info("User %s has set offset to %s", user.id, offset)
 
-    garbage_time = from_utc(
-        datetime(1970, 1, 1, user.time_hour, user.time_minute),
-        None if user.location is None else user.location.timezone.zone,
-    ).strftime(app._("time", "formats"))
+    garbage_time = (
+        datetime.now(pytz.utc)
+        .replace(hour=user.time_hour, minute=user.time_minute)
+        .astimezone(user.location.timezone or pytz.utc)
+    )
 
     await answer.reply_text(
         app._("set_offset_finished", "messages", locale=user.locale).format(
             offset=offset,
-            time=garbage_time,
-            toggle_notice=""
-            if user.enabled
-            else app._("toggle", "messages", locale=user.locale),
+            time=garbage_time.strftime(app._("time", "formats", locale=user.locale)),
+            toggle_notice=(
+                "" if user.enabled else app._("toggle", "messages", locale=user.locale)
+            ),
         ),
         reply_markup=ReplyKeyboardRemove(),
     )
diff --git a/plugins/commands/set_time.py b/plugins/commands/set_time.py
index 166b384..3d190e6 100644
--- a/plugins/commands/set_time.py
+++ b/plugins/commands/set_time.py
@@ -1,13 +1,13 @@
 import logging
 from datetime import datetime
 
+import pytz
 from convopyro import listen_message
 from pyrogram import filters
 from pyrogram.types import ForceReply, Message, ReplyKeyboardRemove
 
 from classes.pyroclient import PyroClient
 from modules import custom_filters
-from modules.utils import to_utc
 
 logger = logging.getLogger(__name__)
 
@@ -55,31 +55,33 @@ async def command_set_time(app: PyroClient, message: Message):
 
         break
 
-    now = datetime.now()
+    # Time we got from the user
+    parsed_time = datetime.strptime(answer.text, "%H:%M")
 
-    parsed_time = datetime.strptime(answer.text, "%H:%M").replace(
-        year=now.year, month=now.month, day=now.day, second=0, microsecond=0
+    # Datetime user means in their timezone
+    user_time = datetime.now(user.location.timezone).replace(
+        hour=parsed_time.hour, minute=parsed_time.minute, second=0, microsecond=0
     )
 
-    user_time = to_utc(parsed_time, user.location.timezone.zone)
+    # Datetime in user's timezone moved to UTC timezone
+    utc_time = user_time.astimezone(pytz.utc)
 
-    await user.update_time(hour=user_time.hour, minute=user_time.minute)
+    await user.update_time(hour=utc_time.hour, minute=utc_time.minute)
 
     logger.info(
-        "User %s has selected notification time of %s",
+        "User %s has selected notification time of %s (%s UTC)",
         user.id,
         user_time.strftime("%H:%M"),
+        utc_time.strftime("%H:%M"),
     )
 
-    garbage_time = parsed_time.strftime(app._("time", "formats"))
-
     await answer.reply_text(
         app._("set_time_finished", "messages", locale=user.locale).format(
             offset=user.offset,
-            time=garbage_time,
-            toggle_notice=""
-            if user.enabled
-            else app._("toggle", "messages", locale=user.locale),
+            time=user_time.strftime(app._("time", "formats", locale=user.locale)),
+            toggle_notice=(
+                "" if user.enabled else app._("toggle", "messages", locale=user.locale)
+            ),
         ),
         reply_markup=ReplyKeyboardRemove(),
     )
diff --git a/plugins/commands/setup.py b/plugins/commands/setup.py
index 3790831..3f60ef9 100644
--- a/plugins/commands/setup.py
+++ b/plugins/commands/setup.py
@@ -1,5 +1,4 @@
 import logging
-from datetime import datetime
 
 from convopyro import listen_message
 from libbot import i18n
@@ -11,7 +10,6 @@ from classes.pyroclient import PyroClient
 from modules import custom_filters
 from modules.search_name import search_name
 from modules.search_nearby import search_nearby
-from modules.utils import from_utc
 
 logger = logging.getLogger(__name__)
 
@@ -74,10 +72,9 @@ async def command_setup(app: PyroClient, message: Message):
 
     await user.update_location(location.id)
 
-    user_time = from_utc(
-        datetime(1970, 1, 1, user.time_hour, user.time_minute),
-        None if user.location is None else user.location.timezone.zone,
-    ).strftime(app._("time", "formats", locale=user.locale))
+    user_time = user.get_reminder_time().strftime(
+        app._("time", "formats", locale=user.locale)
+    )
 
     await message.reply_text(
         app._("setup_finished", "messages", locale=user.locale).format(
diff --git a/plugins/commands/start.py b/plugins/commands/start.py
index 12d2c6c..af11347 100644
--- a/plugins/commands/start.py
+++ b/plugins/commands/start.py
@@ -1,5 +1,3 @@
-from datetime import datetime
-
 from convopyro import listen_message
 from pyrogram import filters
 from pyrogram.types import (
@@ -11,7 +9,6 @@ from pyrogram.types import (
 
 from classes.pyroclient import PyroClient
 from modules import custom_filters
-from modules.utils import from_utc
 
 
 @PyroClient.on_message(
@@ -91,13 +88,15 @@ async def command_start(app: PyroClient, message: Message):
 
         await user.update_location(location.id)
 
-        user_time = from_utc(
-            datetime(1970, 1, 1, user.time_hour, user.time_minute),
-            None if user.location is None else user.location.timezone.zone,
-        ).strftime(app._("time", "formats", locale=user.locale))
+        user_time = user.get_reminder_time().strftime(
+            app._("time", "formats", locale=user.locale)
+        )
+
         await answer.reply_text(
             app._("start_selection_yes", "messages", locale=user.locale).format(
-                name=location.name, offset=user.offset, time=user_time
+                name=location.name,
+                offset=user.offset,
+                time=user_time,
             ),
             reply_markup=ReplyKeyboardRemove(),
         )
diff --git a/plugins/commands/toggle.py b/plugins/commands/toggle.py
index 1b67107..c19e232 100644
--- a/plugins/commands/toggle.py
+++ b/plugins/commands/toggle.py
@@ -1,11 +1,8 @@
-from datetime import datetime
-
 from pyrogram import filters
 from pyrogram.types import Message
 
 from classes.pyroclient import PyroClient
 from modules import custom_filters
-from modules.utils import from_utc
 
 
 @PyroClient.on_message(
@@ -22,10 +19,12 @@ async def command_toggle(app: PyroClient, message: Message):
         )
         return
 
-    user_time = from_utc(
-        datetime(1970, 1, 1, user.time_hour, user.time_minute),
-        None if user.location is None else user.location.timezone.zone,
-    ).strftime(app._("time", "formats"))
+    try:
+        user_time = user.get_reminder_time().strftime(
+            app._("time", "formats", locale=user.locale)
+        )
+    except AttributeError:
+        user_time = "N/A"
 
     if user.location is None:
         await message.reply_text(
diff --git a/plugins/commands/upcoming.py b/plugins/commands/upcoming.py
index 881958d..e34e79c 100644
--- a/plugins/commands/upcoming.py
+++ b/plugins/commands/upcoming.py
@@ -1,5 +1,6 @@
-from datetime import datetime, timedelta, timezone
+from datetime import datetime, timedelta
 
+import pytz
 from pyrogram import filters
 from pyrogram.types import Message
 
@@ -23,11 +24,11 @@ async def command_upcoming(app: PyroClient, message: Message):
 
     date_min = (
         datetime.now(user.location.timezone).replace(second=0, microsecond=0)
-    ).replace(tzinfo=timezone.utc)
+    ).replace(tzinfo=pytz.utc)
     date_max = (
         datetime.now(user.location.timezone).replace(second=0, microsecond=0)
         + timedelta(days=30)
-    ).replace(tzinfo=timezone.utc)
+    ).replace(tzinfo=pytz.utc)
 
     entries = [
         await GarbageEntry.from_record(entry)
diff --git a/requirements.txt b/requirements.txt
index 26c241b..93119a6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,7 @@ aiohttp~=3.9.5
 apscheduler~=3.10.4
 convopyro==0.5
 mongodb-migrations==1.3.1
+pytz<=2023.2
 tgcrypto==1.2.5
 ujson>=5.0.0
 uvloop==0.19.0
diff --git a/validation/examples/user.json b/validation/examples/user.json
index b4765c9..db15f1a 100644
--- a/validation/examples/user.json
+++ b/validation/examples/user.json
@@ -4,6 +4,6 @@
     "enabled": true,
     "location": 1,
     "offset": 1,
-    "time_hour": 18,
+    "time_hour": 16,
     "time_minute": 0
 }
\ No newline at end of file