Hi @johnjackson & @sarahpalombo,
I need your help to understand, is there any way to create a broadcast where i would be able to broadcast reminding messages in Fb messenger & e-mail from google sheet.
Eg: when some one schedules his appointment at 12 pm tomorrow,i want my bot to broadcast a reminder message to the person 3 hours or at some specific time to remind him that he has an appointment booked today.
Thanks in advance
mayank
Sure 
After the bot user has chosen their appointment, how about using the Wait Service where you can use the wait until a date.
(just use the XO icon to insert an output that you’ve collected earlier in the flow i.e their appointment date)
You can also offset this date using {{appointment date}} -3h which would then trigger the next task 3 hours before the time. You’ll just need to reference the recognised date/time.
The flow will wait until this date & time before moving on to the next task.
I don’t think you need to use the broadcast here as each user has a different date it will cleverly wait based on the date and time.
Does that work 
? or do you only hold the appointment dates in a google sheet? - That wouldn’t change much except using a Google Sheet trigger then waiting until the date before you send a message or an email
Hope that helps
Sarah