The time being display constantly is a new update with the date time skill. It leverage the new display manager feature. You can find more about it here
@tikhon try to reboot it by unplugging it and plugging it in. If it’s not fix you may need to re-image your sd card unfortunately 
You can get the image here
https://drive.google.com/file/d/0B_kLZyk84iy_QXAyazFaaDNsS1U/view
Then you need to have an imaging tool
I like this one https://etcher.io/.
stick an sd card into the computer, and etcher should automatically detect it.
After the re-image, make sure to update your mycroft.
sudo apt-get update && sudo apt-get install mycroft-core
You should now be at the latest version.