I’m travelling from London to Japan tomorrow and am wondering if this app will notify me at 8am London or 8am Japan while I’m there (I usually take it 8am London time) - any body experienced this before?

It will notify you at 8 am London time. Once you have a cellular or Wi-Fi connection in Japan and you open up the app it will detect your time charge and display the time you’re supposed to take it at your new location.

Time change*^