This feature is very much discussed in Norway forums. This you can do in Strava, Trainingpeaks and other traininglog apps.
Espessially for all long distance trainers, (running, crosscountry, bike etc) this is very helpful.
This feature should be possible to see on each activity, but also in the report to see how much time used in every sone for a longer period.
It should be easy to make. Please make this feature.
best regards
Ove Veibekk Sparengen
Norway