Do I tell boss about interview?

[Hopeislost]

I have an interview next week for a job in a different civil service department. And not really sure on the etiquette of telling my boss. My interview is at lunchtime so I could feasibly use my lunch break for it. Should I tell my boss?

Didn't your manager have to put their comments on your internal application? Maybe that's stopped.
Why upset the apple cart. Wait and see what happens.

I interviewed for internal civil service jobs without telling my manager. Didn’t get the jobs and I presume they didn’t know.

I then applied for the graduate scheme, got offered a place whilst I was on leave. Came back from leave and everybody knew I was leaving to start the grad scheme! #awkward