If Cell is blank, enter max date

What I need from a formula is this:

If a cell in C1:C20 is blank, enter the most recent date from B1:B20.

I've tried a bunch of different formulas... but its not working out for some reason. Thought I would get a clear head helping me with this....


Thanks!

I understand the way it should work... but its not really working the way I need it to. I've attached the document so you can see what I am working on.

I'm needing to keep the Records page as it is, as the format has to follow a specific way due to regulations from the higher ups....

I also need to keep an ongoing tally of the times someone takes it out for recording purposes. I'm trying to make it so the Stats page automatically updates as in the end it will be a very large document (only about 20 rows, but with many many columns).

What I want is if there is an Out date showing, but no in date, showing a return of the item, that the previous date that it was returned show up in the Stats page.

For example, you will see D. Grant has out H-01, but has not returned it. I need to mark it as last used by the return date of A. Nikonchuk.

In the end, my goal is so also have it state in the Stats - Currently Out page, that D. Grant took it out on April 1. I'm hoping this makes more sense.

Works. Thanks. Do you mind explaining the reason behind why it works, just so I understand and maybe can apply it to other documents I work on in the future?

Thanks!