How long do you make your GAs and why that length?

I typically do 3-4 days. I know the way I feel about trying to enter giveaways and I try to do my own giveaways the same way. 3 days gives people who can't (or just don't) log in every day a chance to still enter, while not being so long I forget about its existence. Occasionally I'll mix it up, such as when I added to the New Year's train, or around a holiday, or even sometimes just to be random.

As somebody entering giveaways, I DESPISE the 1-hour ones. They're basically just throwing stuff to the bots, and guaranteeing that around 98% of members will never even see it. Between 1 hour and 12 hours I find annoying because I can't be on 24/7 (sometimes I only have a chance to log on once a day), and that's not even counting sleeping, so I end up missing a lot of giveaways I would have loved to at least enter.