Either fix or make the automatic scheduler or cron job

So, someone already did the automatic cron job to send out reminders, but the problem is that i get too many repeated reminders and the time is incorrect. Also, if data is missing, other reminders need to be sent, but this part is not implemented. Also, there is a switch to do this in specific time point, because before this time point, there is another reminder system woking now. If you cannot fix the current scheduler's problem, you MUST have the ability to make a new working one. Must be automatic. It is under thinkphp and aws and mysql. DO NOT bid if you are unable to do it or do not understand the environment. Don't waste my time.