Whatsapp - message said delivered, then delivery time changed?

I

iMore Question

So a friend hadn't been online on Whatsapp for a week, so I sent them a message this morning at 10am and it said it had delivered straight away. However, I've just been back online and it now says the message was delivered at 3.10pm - I don't understand!

Did they delete Whatsapp, or me maybe? Why did the delivery time change?

Any help would be much appreciated!

Thanks :)