Помогите с python ботом

now = datetime.datetime.now()

if "s" in unban_time:

unban_time = int(unban_time.replace("s", ""))

elif "m" in unban_time:

unban_time = int(unban_time.replace("m", "")) * 60

elif "h" in unban_time:

unban_time = int(unban_time.replace("h", "")) * 3600

elif "d" in unban_time:

unban_time = int(unban_time.replace("d", "")) * 86400

unban_time = now + datetime.timedelta(seconds=unban_time)

bot.ban_chat_member(message.chat.id, banned, until_date=unban_time)

почему-то забаненный пользователь может зайти раньше unban_time что делать?