I've created several sites with option "Copy Default Settings", updated Operational Hours and Working days, Requesters, Technicians and Technician Groups.
When I create request by requester with new site, Time Spent calculated as Operational Hours are 24x7 but only for working days. For example: working days are Monday and Tuesday, Operational Hours 7:00 - 17:00. Request was created on Monday at 10:00 and closed on Tuesday at 10:00. Request Time Spent value 24h00m, but should be 10h00m.
If I create request by requesters with no site (default settings) and do the same, Request Time Spent value calculated correctly for Default Settings time zone, Operational Hours and Working Days.
Is this a bug or I missed something during site configuration?
The time spent on a request depends on the SLA applied to the request. Check the SLA applied to the request from the request details page and verify the SLA settings for the site under Admin section. In case if the SLA is configured irrespective of operational hours, then the time spent will be calculated round the clock for all the working days.