Cold this morning with no heat
The evohome screensaver said it was 05:52 (it is actually after 08:15). Touched the screen and it indicated 07:39 so I turned off auto clock update (which is beyond Honeywell to get working) and set the time. a few minutes later the heating came on.
The heating went off last night at about the normal time.
No failure email from Honeywell so I guess it was still talking and the android app which is working.
Not yet read all the thread to see if this is a common problem.
Edit: does not seem common and had the update since it was first released.