Update packages get new date?

alan bard newcomer

there are times when many updates appear..  but it seems I used to be able to see that they had a package date that was after my install date 
but now the majority of them don't do that. 
Grovebrook park is in my updates but it's dated 11-07 
while my order date is 11-14 and install date is 11-16
and the package date on the installed one is the same as the one on the update. 
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there are 510 product updates totatling 14gigs listed as ready to download. 
Many of them have a package date after the install date.
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biggest worry is that at lease once in the past the all disaapeared and  I they were magically downloaded.. which in a way was okay... they were gone.. but just like the cat they came back