Maybe 1 day, 7 days, 30 days, and then 1 year recurring?
From what I understand, that would be too much of a memory issue. It's just not practical to have posts open that long. 30 days is about the limit that they're willing to do. But Maybe do a 48-72 hour and a 14-day period. Although, like I said, very few votes come in after the first day.
The current system does somewhat discourage voting after the first day though. I've voted past 24 hours because I found the content worthwhile, but I don't see much of that going on otherwise.
And yeah I have no idea of the technical limitations behind it. XD
I do have every confidence that there is some clever solution to any technical issue that Steem faces.
I think the multiple-cycle voting could improve Steemit. If you can vote multiple times on an older post, you can show that you really appreciate the content. Voting power isn't to be used lightly. It would help organize the content on Steem. A post that was upvoted multiple times during the cycles must obviously be important, and we could add a page for that like for the "new" and "hot" ... call it "oldie but goodie" XD
also there could be multiple ^ symbols and colors that would be awesome to see a post with like "^ ^ ^ ^ *!" next to it ok I'm rambling now.
edit: we could always let the post author choose the schedule. XD - and I realize there are technical issues the way things are now, I haven't read the steem source yet myself, but back in The Day when I did programming there was always some clever, elegant solution to any problem.