As for the fundraiser's duration, I believe the 2014 fundraiser ran for 30 days (December 2 to December 31, 2014).
That's certainly incorrect. https://frdata.wikimedia.org/campaign-vs-amount.csv shows about 200 campaigns started in 2014, excluding sidebar and other "regular" stuff. A campaign can contain hundreds of banners. Some campaigns lasted few hours, most of them several days or weeks.
Because according tohttps://meta.wikimedia.org/wiki/Fundraising_2013 –
"In 2012, we were able to shorten the fundraiser down to nine full days, the shortest fundraiser we've had."
As noted in https://meta.wikimedia.org/wiki/Talk:Fundraising_2012/Report , those numbers are meaningless comparisons. We've been waiting for the number of impressions (at a minimum) for 20 months now.
Nemo