core time
noun1
Business The period of the working day during which all employees are expected to be present, regardless of any flexitime arrangement.
Human resources
- An earlier starting time would interfere with the coordination of core times among the modified flexible schedules […]1987, United States. Federal Service Impasses Panel, Panel Release (issue 253, page 8)
- Under the old flexi-time arrangement, core times (defined partly by the branches' opening hours) were specified.2002, Isik Zeytinoglu, International Industrial Relations Association. European Regional Congress, Flexible Work Arrangements: Conceptualizations and International Experiences (page 154)