Items being updated to state of Done are not having "Closed Date" field set.

[briandye]

Noticing that when I transition a state to Closed it is not getting assigned a date/time in the read-only Closed Date field. Anyway I can accomplish this? Can I use something like updateFields Microsoft.VSTS.Common.ClosedDate,TODAY()?

Would workItemDone work better than setting workItemState to Closed?

[BlueBasher]

workItemDone is for moving in a Kanban board to the Done column.
Setting the Closed Date field is something DevOps does automatically when setting a work item to Closed state.
Do you have a custom Process template that you are using? The default processes all would update that date.