OK, I'll take this bait too, and slightly differently. Long? often. Boring? no, rarely boring, although sometimes tedious. Now I'll comment on why.
As Lyndsey mentioned, our hours are usually really flexible. It is really nice -- I can set up appointments or be with my kids, etc. really easily. But my brain is always going, and I usually work after my kids are in bed. I do some of my best thinking in the shower. Sometimes I really wish I could turn the brain off, to stop thinking about why this piece of computer code isn't working, or why those particular sunspot data are so confusing, etc. Sometimes I wish I had a 9--5 job, like a bank teller or a plumber, and at 5pm the job was done and the rest of life could happen. But as they say, "the grass is always greener", 9-5 jobs don't as easily let you go skiing mid-week! And 9-5 jobs are great for lots of people, but I think I would get bored.
Tedious is debugging code, editing (sometimes), re-doing something for the 17th time because you have found a subtle, really really subtle and exhasperating problem with what you did for the data/interpretation the previous 16 times. But getting to the bottom of that mystery -- what didn't work, and why -- is challenging and often times a lot of fun. Debating (friendly, but often very intense) with colleagues about how to do something or interpret a result is by no means boring. The number of "da...wha???" (sometimes with additional expletives) expressed daily is huge, and it means that you face daily puzzles of a huge range of topics, from "ok, why did I get a result of zero, again, when it clearly ain't!!!???" to working to figure out some of the biggest and most important questions in the universe, and everything in between.
[and to add to Sallie's reply -- when I'm at a solar telescope, I work in the day, work some at night looking at the data so make sure there were no problems, and sleep when we're taking calibration sequences with the telescope! When the observing run is done, then yeah, a few 10-hr sleep nights are usually in short order....]