Why not take in a Duration?

We can only support timeouts in second precision. We can take a duration with that caveat if you think its a must.

it just makes it easy to express minutes in addition to seconds. FWIW, we have other flags that take duration as well and are most likely using a second granularity underneath.

We already have grace-period today in the CLI, and it is always seconds. We have stated that things should say "-seconds" in their API. I don't think we make the argument that everything should be duration, just things that that have wildly disparate values.

If this was a duration, we'd have to chop and round it. I'd be ok with that, as long as it translated to seconds throughout the code.

So this is consistent with --grace-period being in seconds, so keeping as is.