For example, my local timezone is +3 UTC and I want to run job every working day at 23:00 UTC.

launch_time.tzinfo is None so it's expected to be interpreted as 23:00 UTC.

launch_time = dtm.time(hour=23)
job = job_queue.run_daily(run_once, launch_time,
                          days=(0, 1, 3, 4))

Since launch_time.tzinfo was None, job.tzinfo is also equals None because of the following code from JobQueue.run_daily

Let's assume now is 23:00 UTC Friday.

The following code from JobQueue.tick won't run the job because

1. datetime.datetime.now(None) returns local time and local time now is 02:00 Saturday.
2. then datetime.datetime.now(job.tzinfo).date().weekday() will return 5
3. any(day == current_week_day for day in job.days) will return False because we're looking for (0, 1, 3, 4)
   So job won't be run until 23:00 UTC Sunday.
   

   python-telegram-bot/telegram/ext/jobqueue.py

   Lines 275 to 280 in 3d42df3

   	if job.enabled:
   	try:
   	current_week_day = datetime.datetime.now(job.tzinfo).date().weekday()
   	if any(day == current_week_day for day in job.days):
   	self.logger.debug('Running job %s', job.name)
   	job.run(self._dispatcher)

And one more thing - when #1685 will be merged, in the described case Job.next_t will be returning local time when utc time is expected:

    @property
    def next_t(self):
        return datetime.datetime.fromtimestamp(self._next_t, self.tzinfo) if self._next_t else None