Chances are you have already sent a wrong message to a friend or a group in WhatsApp.
If you notice it quickly, you can go there, and simply delete the message for everyone. (To bring up the Delete for Everyone option, simply tap and hold the unwanted message and hit the Delete symbol).
But after some time (few minutes, i believe it’s 7 minutes) you are no longer able to do it.
Fortunately, there is a way to bypass this restriction - and delete for everyone even hours or days later!
It’s not straightforward, but also is not so complicated - and worth to do it, mainly if the message is something particularly embarrassing. 
It is incredible, but the SOLUTION is very simple: you just need to change your phone’s clock!
- Note the time of the message you want to Delete for Everyone
- Enable Airplane mode
- Close WhatsApp
- Change both Time and Date in your phone’s Settings menu, to a moment earlier then the moment the wrong message was sent.
- Open WhatsApp
- View the chat, locate the message and tap and hold it
- Click the Delete symbol
- Select Delete for Everyone.
Done! 
Now, let’s back our phone to how it was before: close WhatsApp again, switch off Airplane mode and change your phone’s data and time back to normal.
I am not sure how many days you can “come back” in time, but i have already deleted for everyone a message i’ve sent 5 days ago.
But at least for me, it was a great tip, and already saved my from embarrassing. 
That’s it for today folks. But if you’re the kind that like to see examples…
Suppose I’ve sent an embarassing message at time 17:13.
If I want to delete it for everyone, right after sending it, i simply click Delete icon, and select DELETE FOR EVERYONE.
But if I try to do it later, it is not possible anymore - i can onlye DELETE FOR ME.
So, let’s do workaround. I will not paste here how to change my phone Date/Time, because it vary a lot from phone to phone.
But after following the steps above, I am able to delete it. 
And voilá!
