Looks like you'll have to take some with you.

When a person is on high doses >25mg aren't they advised to wear a medical bracelet?

Cortisol levels are highest around 7am and more or less drop throughout the day.

I don't think too many people take it after mid-afternoon.

This is one reason why I like to include some pregnenolone if tests suggest it. Besides being more natural and you are supporting a larger number of hormones, I'd expect a smoother effect.