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[bdjakaria76]

Set the desired date and time for sending.
Some might offer options like "Ask me before sending" or recurring messages. Caution: Be mindful of the permissions these apps require and their privacy policies. They might not be as reliable as API-based solutions and often need your phone to be on and connected to the internet at the time of sending.
iOS Shortcuts App:

iPhone users can leverage the built-in "Shortcuts" app to create personal automations that trigger a WhatsApp message at a specific time. However, this typically requires a manual tap to confirm sending when the scheduled time arrives. It doesn't truly send it automatically in the background.
General steps:
Open the Shortcuts app.
Go to Automation and tap + to create a Personal Automation.
Select Time of Day and set your desired time.
Add an action: search for Text and enter your message.
Add another action: search for WhatsApp and select Send whatsapp number list Message Through WhatsApp.
Choose the recipient.
Disable Ask Before Running if you want it to run without your confirmation (though this might not work reliably for WhatsApp sending without intervention).
WhatsApp Web Extensions (e.g., Blueticks, Wasavi):

These are Chrome extensions that add scheduling functionality to WhatsApp Web. They operate within your browser.