Claus Busch wrote:

Am Fri, 25 Apr 2014 00:27:10 +0000 (UTC) schrieb Auric__:

I see now that my previous examples make it look like the times are in
groups of 2, but they're not. Any of the times might be blank. Here's a
selection from my log showing several possibilities:

if your log data is in correct order (first login to last login) you
could try it with:
=MOD(INDEX(B1:G1,MATCH(0,B1:G1,-1))-INDEX(B1:G1,MATCH(TRUE,B1:G1<"",0)),
1)
This is an array formula to enter with CTRL+Shift+Enter

Wow. Thank you. Certainly beyond what I would've thought to try.

I am still thinking for a solution if the times are not in order.

It's rare, but yes, there are entries where I have something like this:

22:01 22:12 22:15 22:20 22:14

In this case, your formula returns 0:13, while the actual value should be
0:19.

I'm wondering if maybe I should just add some conditional formatting to the
problem column (H) to highlight anything over, say, an hour. While it isn't
what I want, it would make problems stand out visually, for immediate manal
editing.

--
It's so adorable when you nerd rage!