Hi ​@samar ,
You can only send messages using automations within the 24-hour window. Here is a complete article from ManyChat on this topic:
https://help.manychat.com/hc/en-us/articles/14281199732892-How-to-send-messages-outside-the-24-hour-and-7-day-windows-in-Messenger-and-Instagram

Let me know if this was helpful.

You have 24-hours after the last form of engagement your contact made (a reply, Quick Reply click, etc). What are you looking to do with the automation?

sorry, wrong message