You are now able to schedule messages to WhatsApp broadcast lists in the same way you schedule to regular contacts or Groups.
1. Enter scheduling screen
2. Click to add recipients, and add the Broadcast list you want to schedule to
3. Set the date & time.. and that's it!
IMPORTANT: Please note that if the broadcast list still has default name given to it when it was first created, then the scheduling will fail. Please edit the default name and change to any other text so that scheduling is successful.