release cadence for Q and R

[Allison Randal]

At UDS-O, we talked about balancing the 6-month cycle from the current
24/28 split towards a more even split. The general consensus was to keep
the long 28 week cycle for P, since it's an LTS, but discuss more for Q
and R.

For context, I did a little walk down memory lane:

https://wiki.ubuntu.com/AllisonRandal/ReleaseCadence

Turns out, we've only had an actual 26 week cycle twice in the history
of Ubuntu (Gutsy and Lucid), and never back-to-back. The longest cycle
ever was 33 weeks (Dapper), immediately followed by the shortest cycle
ever at 21 weeks (Edgy). The most common cycle length was 27 weeks
(Breezy, Hardy, Intrepid, Karmic). Maverick was 24 weeks, Natty 28, and
Oneiric and P follow the same 24/28 split.

In the current draft schedules for Q and R we continue the 24/28 split:

Q: October 11, 2012 (24 weeks)
R: April 25, 2013 (28 weeks)

The concern raised at UDS is that 24 week cycles are difficult for
upstreams working to synchronize their cadence with ours. The simplest
proposal is to bump Q one week later, and R one week earlier for:

Q: October 18, 2012 (25 weeks)
R: April 18, 2013 (26 weeks)

And after that follow a more-or-less 26/26 split (barring interference
by international holidays, etc). Would this change be helpful or harmful
for you? If so, could you share a bit about how? Is the change adequate
to address the needs of upstreams?

To help our wonderful UDS planners (who need to know when to book UDS
space for us), I'll summarize the thread for this Friday's release
meeting, and we can discuss any remaining questions there.

Thanks all,
Allison