diff --git a/packit_service/utils.py b/packit_service/utils.py
index ab8da35a5..d65b48788 100644
--- a/packit_service/utils.py
+++ b/packit_service/utils.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 import logging
+from datetime import datetime, timezone
 from io import StringIO
 from logging import StreamHandler
 from typing import List, Tuple
@@ -121,3 +122,33 @@ def collect_packit_logs(buffer: StringIO, handler: StreamHandler) -> str:
     packit_logger.removeHandler(handler)
     buffer.seek(0)
     return buffer.read()
+
+
+def is_timezone_naive_datetime(datetime_to_check: datetime) -> bool:
+    """
+    Check whether the given datetime is timezone naive.
+
+    Args:
+        datetime_to_check: datetime to check for timezone naiveness
+
+    Returns:
+        bool: whether the given datetime is timezone naive
+    """
+    # https://docs.python.org/3/library/datetime.html#determining-if-an-object-is-aware-or-naive
+    return (
+        datetime_to_check.tzinfo is None
+        or datetime_to_check.tzinfo.utcoffset(datetime_to_check) is None
+    )
+
+
+def get_timezone_aware_datetime(datetime_to_update: datetime) -> datetime:
+    """
+    Set timezone for datetime so that it is timezone-aware.
+
+    Args:
+        datetime_to_update: datetime to update
+
+    Result:
+        timezone-aware datetime
+    """
+    return datetime_to_update.replace(tzinfo=timezone.utc)
diff --git a/packit_service/worker/handlers/copr.py b/packit_service/worker/handlers/copr.py
index 1fb8329e7..faa2e8458 100644
--- a/packit_service/worker/handlers/copr.py
+++ b/packit_service/worker/handlers/copr.py
@@ -45,7 +45,12 @@
     AbstractPRCommentEvent,
 )
 from packit_service.service.urls import get_copr_build_info_url, get_srpm_build_info_url
-from packit_service.utils import dump_job_config, dump_package_config
+from packit_service.utils import (
+    dump_job_config,
+    dump_package_config,
+    is_timezone_naive_datetime,
+    get_timezone_aware_datetime,
+)
 from packit_service.worker.events.enums import GitlabEventAction
 from packit_service.worker.helpers.build import CoprBuildJobHelper
 from packit_service.worker.handlers.abstract import (
@@ -148,13 +153,8 @@ def get_packit_github_installation_time(self) -> Optional[datetime]:
 
     def run(self) -> TaskResults:
         installed_at = self.get_packit_github_installation_time()
-        # transform timezone-naive datetime
-        # https://docs.python.org/3/library/datetime.html#determining-if-an-object-is-aware-or-naive
-        if installed_at and (
-            installed_at.tzinfo is None
-            or installed_at.tzinfo.utcoffset(installed_at) is None
-        ):
-            installed_at = installed_at.replace(tzinfo=timezone.utc)
+        if installed_at and is_timezone_naive_datetime(installed_at):
+            installed_at = get_timezone_aware_datetime(installed_at)
         if self.package_config.srpm_build_deps is not None or (
             installed_at and installed_at > DATE_OF_DEFAULT_SRPM_BUILD_IN_COPR
         ):
diff --git a/packit_service/worker/monitoring.py b/packit_service/worker/monitoring.py
index 893be4297..8607f1325 100644
--- a/packit_service/worker/monitoring.py
+++ b/packit_service/worker/monitoring.py
@@ -3,10 +3,12 @@
 
 import logging
 import os
-from datetime import datetime, timezone
+from datetime import datetime
 
 from prometheus_client import CollectorRegistry, Counter, push_to_gateway, Histogram
 
+from packit_service.utils import is_timezone_naive_datetime, get_timezone_aware_datetime
+
 logger = logging.getLogger(__name__)
 
 
@@ -18,10 +20,10 @@ def measure_time(begin: datetime, end: datetime) -> float:
     Returns:
         float seconds between begin and end
     """
-    if begin.tzinfo is None or begin.tzinfo.utcoffset(begin) is None:
-        begin = begin.replace(tzinfo=timezone.utc)
-    if end.tzinfo is None or end.tzinfo.utcoffset(end) is None:
-        end = end.replace(tzinfo=timezone.utc)
+    if is_timezone_naive_datetime(begin):
+        begin = get_timezone_aware_datetime(begin)
+    if is_timezone_naive_datetime(end):
+        end = get_timezone_aware_datetime(end)
 
     return (end - begin).total_seconds()