I already used the sdk 🙂
what does empty runtime mean?

My guess is that it wasn't run yet (drafts for example)

Hi CooperativeOtter46 ,

I think the best way would be to use the API (You can use the SDK but I don't think it is so easy to filter times)
Use https://clear.ml/docs/latest/docs/references/api/tasks#post-tasksget_all api call to to get all the tasks according to the time frame & filtering you want and then sum up the run time from all experiments returned 🙂

'active_duration' is the right field?

👍

To use the SDK see here:
https://clear.ml/docs/latest/docs/references/sdk/task#taskget_all