Comes out as 0 on two of mine, as well, and easily wins the one where it doesn't.  Well done, Chris!

John

Replace the line that ends "AS COUNT_of_Interface_Caption".  You need to make sure you understand it though, and not just use it because someone off the internet gave you it.  It'll...

SUM(    CASE
            WHEN Out_AverageBps/OutBandwidth*100.0 > 90 AND In_AverageBps/InBandwidth*100.0 > 90 THEN 1
            ELSE 0
        END
        ) AS COUNT_of_Interface_Caption

John

Not enough information to help you here.  Some possibilities:

(1) Differences in the data on source and/or destination
(2) Differences in hardware (processors, memory and so on)
(3) Differences...

...
WHERE calltime BETWEEN
    CASE
        WHEN dept IN (
            SELECT dept FROM dept WHERE time_zone = 'est'
            ) THEN '09:02:00.0000000'
        WHEN dept IN (
            SELECT dept    FROM...

This isn't what an RDBMS is designed for, so performance won't be great.  But you can try this (feel free to correct any syntax errors that may have slipped in):

Thanks for the test harness, Jason.  My pride was dented when I saw I finished last!  I tried it out on three of my own servers and my results were...

I don't have DDL or sample data for your dept table, so I can't test, but something like this:
WITH TimesasInt AS (
    SELECT
       ...

d and ISNULL(c.Folldate, '01-jan-1900') are the first two arguments of the DATEDIFF function.  d means days, and ISNULL(c.Folldate, '01-jan-1900') means c.Folldate unless it's NULL, in which case 1st January 1900.  So...

... and if you don't even include in your sample data the columns that are in your query, we really aren't...