wrote in
ups.com:

Quite right. We should be required to pack chutes weekly, just to be
on the safe side.

Of course, it's actually illegal to fly with an out-of-pack-date chute.
If we were legally required to pack weekly, then the practical reality
is that many more pilots might choose to fly without their chutes. The
result of a one-week requirement would not be that everyone would carry
better safety equipment (parachutes repacked recently), but that many
of us would carry no safety equipment at all. One pilot dead because
of a law like this would be one pilot too many.

We already have a law like this. The regulation currently reads, "No
pilot of a civil aircraft may allow a parachute that is available for
emergency use to be carried in that aircraft unless...it has been
packed by a certificated and appropriately rated parachute rigger
within the preceding 120 days"
(snip)

About 20 years ago there was an article in Australian Gliding showing the
results of tests of parachute opening time versus time since repack. I
don't remember the details but the fastest opening times were found to be
at one year since repack.
-Bob Korves