Early key renewal doesn't work with old(er) times

Hello!

I noticed some interesting behavior that I wanted to share that seems unexpected.

When I attempt early key renewal with a relatively recent timestamp (within the past few seconds or so), it works exactly as expected! Specifically I've been using the environment variable approach described here: https://github.com/bitnami-labs/sealed-secrets#early-key-renewal. However, when I attempt the same procedure with an older timestamp, a new key isn't created.

For example, I edit the Deployment (perhaps not too relevant, but I did this live via an edit in K9S) to add the following stanza to the spec for the controller container:

        env:
        - name: SEALED_SECRETS_KEY_CUTOFF_TIME
          value: "Fri, 10 Sep 2021 10:59:41 -0400"

For greater context, here's more YAML to show where exactly I placed it:

    spec:
      containers:
      - command:
        - controller
        env:
        - name: SEALED_SECRETS_KEY_CUTOFF_TIME
          value: "Fri, 10 Sep 2021 10:59:41 -0400"
        image: quay.io/bitnami/sealed-secrets-controller:v0.16.0
        imagePullPolicy: Always
        livenessProbe:
          failureThreshold: 3

As I type this, it's 12:14 ET, which is a little over an hour from the time in the value field above. When I apply this, I see that Kubernetes creates the new pod, but a new secret is not created. If I again edit the container spec and change the value of the existing environment variable to a more recent time, such as 12:14:00, I see that the pod is again refreshed and a new key is created.

I dug into the code and don't quite understand why this would be happening, it seems like a fairly straightforward comparison: https://github.com/bitnami-labs/sealed-secrets/blob/d15c388248912213c930d1dc5b0f84c627bca3ea/cmd/controller/main.go#L148

I do see that the documentation specifically says to pass the "current timestamp", but I suppose I didn't read that literally.

Bottom-line, is this expected functionality?

Thanks a ton 😁 , Matt White