You can make changes to multiple tasks at once with bulk action tool.
To activate bulk actions:
Click on the two-tick icon above the task list.
Select "Multiselect" from the three-dot menu.
Press command ⌘ (Mac) or ctrl (Windows) on the keyboard.
Note: The multitasking menu opens when you tick the task(s).
As a bulk action, you can:
Delegate tasks to users
Mark as extra work
Mark as important
Add time entries - add the same time to multiple tasks or divide the time entered equally between tasks.
Mark tasks as done