Vacation schedule delegation

We need a feature to allow another person delegation rights to set a resource's vacation dates. Currently, only the resource can add vacation dates to their schedule. If they go out on vacation or do not update their schedule, it does not get reflected in the calendar and this impacts the project's timelines. It would be helpful to allow a project manager whose assignees are on their project the right to edit their vacation schedule.

In addition, any additional control over a resource's schedule that would affect a project's projection would be helpful for accuracy.