How to set dates on data usage...

[touchy66]

... on my wife's phone.
Huawei RIO-L01 (G8)
EMUI 4.0
Android 6.0.1
Build RIO-L01C109B311

The Data Traffic Management area used to have an area for this on the main screen and under notifications but after the updates (as shown above) and under notifications but this has since gone. Settings only has paramaters for total data available and usage reminders.

Any guidance is gratefully received.

Thanks.