Now, you can schedule WhatsApp messages on your Android smartphone. This means you can schedule message by setting the time for it. This can be done by using another useful app. Follow the steps to schedule your messages.
a) Download and install WhatsApp Scheduling App in your Android smartphone.
b) After the installation, open the app, and it will ask you for Superuser permission for further process. Grant it the permission.
c) Click on the icon provided in front of the pending messages, and then choose "Contact" for which you want to schedule message. It can be an individual contact or a group.
d) Type your message and set the scheduling time.
e) Click on Add, and your message will be set under the Pending Messages tab, and will be sent on the scheduled time.