7940 / 7960 DST change and CUCM 6.x - 7.x

Last week I was working on a set of problem phones on a really old version of CUCM.  The problem was that when daylight savings time ended, all the newer phones rolled back an hour with the change of NTP based on the Date/Time group but the older 7940s and 7960s did not.  This is a constant yearly issue with this particular client's CUCM as they are on 6.x.  After doing some research I found a bug that affects the 6.x train and also appears to go all the way to 8.0.  This bug essentially holds the 40s and 60s back and you either have to manually change the time, update the CUCM with a .cop file, or just wait a week for them to change.

The weird part about all of this is that I changed it earlier this year to bump it ahead an hour and I didn't have to change it again afterwards.  I cycled the time back to -7 time since I am on central time and everything was fine.  Later last week I got a call that their phones had once again went forward an hour.  This didn't make sense at all.  I went in and did a screen cap of the 7940 and sure enough, it was showing eastern time again.  I set the date/time group back to central time and this ultimately resolved the issue.

So the lesson learned is:

1. Upgrade your CUCM
2. Get rid of those ancient phones
3. Upgrade and get rid of the phones
4. Wait a week for the time to change
5. Update the CUCM with a COP file

Why this issue still persists is beyond me.  This is something that was going on back when 6.x and 7.x were still supported over 4 years ago or so.  It should have been fixed then but never was.  Still, all the more reason to get off of an MCS server and move over to a BE6k or BE7k!