WhatsApp will soon let you schedule messages
It should become possible to schedule sending a message for at a later time. This is according to clues in the code of the latest version of WhatsApp. In doing so, the popular messaging service follows several other apps that have offered the functionality for some time, such as Telegram and Signal. There, you can schedule a message by holding down the send button. Scheduled messages can be found in the contact screen, so you can quickly access them. Until the moment of sending, you can cancel sending or still edit the message.

At the moment, the feature has only surfaced in the latest version of WhatsApp for Apple iOS. For Android, the feature has not yet been found in the code, even in the beta version. It is not known when the functionality will be rolled out. It may well take a while. After all, we have also been waiting for a feature that allows you to set a username for some time. That feature, too, is still in development after years.
Via Wabetainfo