diff --git a/test/run_multiple_tests.py b/test/run_multiple_tests.py
new file mode 100755
index 00000000..d0da9ff7
--- /dev/null
+++ b/test/run_multiple_tests.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""
+Test script, for testing different situations, like:
+    - different day_start times
+"""
+
+import json
+import os
+import sys
+from datetime import datetime
+from threading import Thread
+from time import sleep
+from unittest.mock import patch
+from zoneinfo import ZoneInfo
+
+import time_machine
+
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+# from ffplayout import playlist
+
+# set time zone
+_TZ = ZoneInfo("Europe/Berlin")
+
+
+def run_at(time_tuple):
+    dt = datetime(*time_tuple, tzinfo=_TZ).strftime("%Y-%m-%d  %H:%M:%S")
+
+    @time_machine.travel(dt)
+    def run_in_time_machine():
+        desktop.output()
+
+    print(f'simulated date and time: {dt}\n')
+
+    run_in_time_machine()
+
+
+def run_time(seconds):
+    """
+    validate json values in new thread
+    and test if source paths exist
+    """
+    def timer(seconds):
+        print(f'run test for {seconds} seconds...')
+        sleep(seconds)
+        terminate_processes()
+
+    terminator = Thread(name='timer', target=timer, args=(seconds,))
+    terminator.daemon = True
+    terminator.start()
+
+
+def print_separater():
+    print(79 * '-')
+    print(79 * '-')
+
+
+def shorten_playlist(file):
+    json_object = json.load(file)
+    del json_object['program'][-1:]
+    return json_object
+
+
+def extend_playlist(file):
+    json_object = json.load(file)
+    elems = json_object['program'][:2]
+    json_object['program'].extend(elems)
+    return json_object
+
+
+def clear_playlist(file):
+    return {}
+
+
+@patch('ffplayout.playlist.valid_json', shorten_playlist)
+def run_with_less_elements(time_tuple):
+    run_at(time_tuple)
+
+
+@patch('ffplayout.playlist.valid_json', extend_playlist)
+def run_with_more_elements(time_tuple):
+    run_at(time_tuple)
+
+
+@patch('ffplayout.playlist.valid_json', clear_playlist)
+def run_with_no_elements(time_tuple):
+    run_at(time_tuple)
+
+
+if __name__ == '__main__':
+    from ffplayout.output import desktop
+    from ffplayout.utils import (_playlist, terminate_processes)
+
+    print('\ntest playlists, which are to short')
+    _playlist.start = 0
+    run_time(200)
+    run_with_less_elements((2021, 2, 15, 23, 58, 3))
+
+    print_separater()
+
+    print('\ntest playlists, which are to long')
+    _playlist.start = 0
+    run_time(200)
+    run_with_more_elements((2021, 2, 15, 23, 59, 33))
+
+    print_separater()
+
+    print('\ntest playlists, which are empty')
+    _playlist.start = 0
+    run_time(200)
+    run_with_no_elements((2021, 2, 15, 23, 59, 33))
+
+    print_separater()
+
+    print('\ntest transition from playlists, with day_start at: 05:59:25')
+    _playlist.start = 21575
+    run_time(200)
+    run_at((2021, 2, 17, 5, 58, 3))
+
+    print_separater()
+
+    print('\ntest transition from playlists, with day_start at: 20:00:00')
+    _playlist.start = 72000
+    run_time(200)
+    run_at((2021, 2, 17, 19, 58, 23))