Depends on the business, for example in consulting, billable hours rule. The mention of "calls" would be consistent with this. And in a lot of workplaces, desk

Depends on the business, for example in consulting, billable hours rule. The mention of "calls" would be consistent with this. And in a lot of workplaces, desk time well exceeds 40 hours a week. In addition, it could be a way of encouraging employees to return to the office. What is fair depends on what a person is paid the kind; of work they are doing; local custom; industry standards; etc. Finally, it might be a bullshit requirement based on a bullshit directive from above and responding with a bullshit time sheet is reasonable. Or in the case of billable hours, assigning your time to billable hours is what matters to the bottom line and your productivity is somewhat incidental and only loosely correlated to the value of your time to your employer. Indeed in billable hour situations, management reworking timesheets is not particularly rare. Good luck.