When you want to copy a work order or part of a work order to another date, and leave the original work order, then use the options Copy or Divide for that. Both options are explaind in further detail on this page.
Follow the below steps to place a copy of a work order on another date, while the original work order remains unchanged:

The work order is now copied to the memory of the computer.

Plan-IT creates a copy of the original work order on the new spot. The copied work order now gets a new work order number, with a reference to the original work order. The copied work order has the same operations, extra operations, and checkmarks as the original work order. Editing these options in the copied work order has no effect on the original work order.
When dividing work orders, Plan-IT Workshop splits a work order in two separate work orders, with the original time duration of the work order being divided between the two new work orders. This way, you can move part of an existing work order to another date, time, or mechanic.

A pop-up window with a slider bar appears now, with which you can indicate how you want to divide the work order. By moving the slider to the left or right, you can indicate in percentages how the time duration of the work order should be divided between the two new work orders.

After you have set the percentage, click on the Divide button. The work order is split by the chosen percentage, rounded off to quarters of an hour.

The copy work order (indicated by the yellow dot in the bottom right corner) can now be moved to another date, time, or mechanic by dragging, cutting and pasting it, or by temporarily placing the work order on the clipboard and then navigating to the preferred date.