Interesting, please let us know if this seems to fix things.

Your results are incomplete. You have more than 2 dates in the source you've listed. That's what I mean by calculating all results. Don't pick a few and think you've...

First, you need to set up test instances and test. DO NOT JUST TAKE ADVICE. You have to test things. You don't need a copy of production, but you need...

It's just good coding. Checking for potential and common problems is what we should all do and rarely do. If there's one good thing about the cloud, it's that these...

What data is in the empty spaces? This isn't Excel. Either a null, blank space, something is there.

Look at dbatools.io as well. You could use a scheduled task that would be easy and trivial to write with their cmdlets.

I'd send an email with the observation and recommendation to my manager and keep a copy. Then let them decide what to do.

Ensure you've  met your obligations, but...

Hmmm, I hadn't noticed. I'll check.

Glad it's working and thanks for providing an explanation of what worked.

Is it just the three columns? You can use CASE to check for a meeting and calculate a time, then sum those up. If no meeting, return a 0 to...

Re: The editorial
It's interesting to ask us to perhaps behave or choose in ways that get along with or go along with the flow of wherever we are, but...

Have you looked at first_Value? You can partition this and get the first lead date for a code item.

You do lose some SQL 2014 features. New keywords don't work, as the purpose of compatibility mode is to allow older code that might have a keyword, such as the...

Are you unsure of how to do this?

insert target
select columns from source s
  inner join target t
 on s.date <> t.date