How is one to conduct a proper experimental program when one's subjects are snatched away at inconvenient and arbitrary times?

The idea of an audience at any arbitrary time doesn't appeal.

I asked, for it seemed like a rather arbitrary time to start counting trucks.

Note that since this ratio is independent of time, one can take arbitrary times and achieve similar triangles.

Time t is an arbitrary time in the plateau region of C(t).

That can be done by measuring an arbitrary time both the start and stop events and subtracting.

And so just restarting my computer at an arbitrary time is not an option for me.

Let's set an arbitrary time every hour on the hour for reply.

Monk was elusive, unyielding, at times arbitrary and cold.

He saw no reason to delay until thirteen hundred because of some arbitrary time he'd set.