Total Hours Watched Metric

The Bitmovin Dashboard's metric Total Hours Watched is the total time people spent watching. This means that it's the sum of all the time users spent in the playing state.
Thus the corresponding API query is:

queryBuilder
  .sum('PLAYED')
  .licenseKey('YOUR_LICENSE_KEY')
  .between(fromDate, toDate)
  .filter('PLAYED', 'GT', 0)
  .query();

As all Bitmovin Analytics queries it supports .groupBy and .interval.