Proposal: Save expiration time of a quest in the db so only non expired quests are being used

[Bart274]

You have the coordinates of a pokestop, based on those coordinates you can get the timezone and determine the local midnight time of the pokestop and know the expiration time of the quest because of it.
This way you can have a clean map, clean set of pokestops after midnight,...

In RocketMapPlusPlus the following logic was used:

                    utcnow_datetime = datetime.utcnow()
                    quest_json = fort_search_response_json["challengeQuest"]["quest"]
                    quest_pokestop = pokestops.get(quest_json["fortId"], Pokestop.get_stop(quest_json["fortId"]))
                    pokestop_timezone_offset = get_timezone_offset(quest_pokestop['latitude'], quest_pokestop['longitude'])
                    pokestop_localtime = utcnow_datetime + timedelta(minutes=pokestop_timezone_offset)
                    next_day_localtime = datetime(
                        year=pokestop_localtime.year,
                        month=pokestop_localtime.month,
                        day=pokestop_localtime.day
                    ) + timedelta(days=1)
                    next_day_utc = next_day_localtime - timedelta(minutes=pokestop_timezone_offset)

for the timezoneoffset, the following code was used:

def get_timezone_offset(lat, lng):
    args = get_args()

    (timezone_offset, status) = get_timezonefinder_timezone_offset(lat, lng)
    if status != "OK":
        (timezone_offset, status) = get_gmaps_timezone_offset(lat, lng, args.gmaps_key)
        if status != "OK":
            timezone_offset = args.quest_timezone_offset

    return timezone_offset


def get_timezonefinder_timezone_offset(lat, lng):
    from pytz import timezone
    import pytz

    utc = pytz.utc

    try:
        today = datetime.now()

        tz = tf.certain_timezone_at(lat=lat, lng=lng)
        if tz is None:
            tz = tf.timezone_at(lat=lat, lng=lng)
            if tz is None:
                tz = tf.closest_timezone_at(lat=lat, lng=lng)
                if tz is None:
                    return (0, "UNKNOWNN_TIMEZONE")

        tz_target = timezone(tz)
        today_target = tz_target.localize(today)
        today_utc = utc.localize(today)

        status = "OK"
        timezone_offset = int((today_utc - today_target).total_seconds() / 60)
    except Exception as e:
        log.exception('Unable to retrieve timezone from timezonefinder: %s.', e)
        status = 'UNKNOWN_ERROR'
        timezone_offset = None

    return (timezone_offset, status)

def get_gmaps_timezone_offset(lat, lng, gmaps_key):
    try:
        r_session = requests.Session()
        response = r_session.get((
            'https://maps.googleapis.com/maps/api/timezone/json?' +
            'location={},{}&timestamp={}&key={}').format(lat, lng, time.time(), gmaps_key),
            timeout=5)
        response = response.json()
        status = response['status']
        timezone_offset = (response.get('rawOffset', 0) + response.get('dstOffset', 0)) / 60
    except Exception as e:
        log.exception('Unable to retrieve timezone from Google APIs: %s.', e)
        status = 'UNKNOWN_ERROR'
        timezone_offset = None

    return (timezone_offset, status)

[Mygod]

Another way to read timezone could be to use GetPlayerResponse.player_data.time_zone_offset_ms. However, there might be a disconnect from the time GetPlayer is requested until FortSearch is initiated, or if the player is on the borderline of two timezones... Never mind.