Yes I do have the server time offset in the Joomla Global settings to UTC -5:00.
This was the start of my confusion. I have correct time throughout the site except for the uddeim message timestamps.

Do you have the correct time when you create/modify an article? There are lots of components which use the server time without any corrections, so these components use the wrong time.
As I said before, uddeIM uses the same method to get the correct time as Joomla does, so when you create an article or a PMs both should have the same time.

Are you sure that you have installed Joomla correctly? As far as I can remember you can enter the server offset during the installation process.

You can modify this globally in configuration.php:
$config_offset = nnn;

In the backend it is disabled, so you cannot change this value in the backend.

I just checked configuration.php as you suggested. It is set to -5

$offset = '-5';

When creating an article I have the proper time on creation and on modification. Well technically one hour behind due to Daylight Savings, but it is correct based on Eastern Standard Time.

I am confident that Joomla is installed correctly. This is the only anomaly that I have come across.

I'm not sure if this makes a difference, but I am using Joomla 1.5.2

willh20 wrote:

After some trial and error I found that this setting gives me the correct timestamps.

[code:1]$rightnow=time()-($mosConfig_offset*2160);[/code:1]

This must be due to the fact that I want my time settings in UTC -5:00 and my server sits in UTC -8:00

Thank you very much for your help.

I doubt that this is correct since time() returns a timestamp in seconds and $mosConfig_offset is mesaured in hours. So 3600 is the correct value here. You can adjust the time by increasing or decreasing the offset only, e.g.

[code:1]$rightnow=time()+(($mosConfig_offset + adjustValueHere )*3600);[/code:1]