How to set date and time

Don’t seem to find any place for being able of change the date and time on device

I wrote a reply and now it is gone

Open phone to app.
Turn on EKGraph.
Go to settings on app. & set them, hit Save.
Sync the app. with phone.
Phone should say setting changes are made.
Do a reading on EKGraph.
Sync phone.
Everything should now read proper!