Leave tube amp on all day?

I've just purchased my first piece of tube gear, a Cary SLI-80 integrated. What's the best for tube life? Leave it on all day or turn it on only when it's used?

On days I'm home, I may listen an hour in the morning and a couple hours in the evening. If I leave it on all day, to get 2-3 hours of listening time, it'll be on for 12+ hours. This means the power tubes won't last more than a year? If I turn it on and off 2 to 3 times each day, will the tubes last longer?

If it's best to just leave it on all day, then is it advisable to leave it on over night as well for multiple days? Turn on Friday evening and turn off Sunday evening?
As Larryi suggests I would consult with cary and get their recommendation. However, I for one would not leave a tube amp on all day even if it wasn't unattended. If you are listening for short periods of time in the morning and then again in the evening I would turn it off between sessions. I would not even think of leaving it on overnight or over the weekend. The reasons being is tube life, as it will shorten if left on, but more importantly for safety reasons.Tubes can and do short out which could cause a fire especially if left unattended.

Chuck a Little over the top, I would saayLeave it on and donrt be so paranoid. Its consumer electronics, not garage gear
I just simply would turn it on and off. Unless you use cheap tubes. That's what will cost you. The rest of the amp even if you shorten it's life should last 10+ years under bad conditions.
If you're going to be using the amp for the majority of the day at various times, leave it on in standby mode. If you aren't going to use it for very long each time and / or have extended periods between use, turn it off and on as needed using your own judgment.

Tubes deteriorate with use, even in standby mode with most designs. Not only that, but some tubed amplifier designs can become hazardous / start on fire when a tube fails. As such, i would not leave tubed amplifiers on and unattended for extended periods of time. Obviously, this is my point of view, so take it for what it is worth.

I say this because most properly designed tubed circuits with reasonably strong tubes stabilize in appr 20 - 30 minutes of use. There is little to no sonic benefit in leaving a tubed power amp fired up 24/7 other than the reduction of in-rush current to the tubes.

Bare in mind that i'm talking about output level tubes here, NOT line level tubes such as found in a preamp, CD player, DAC, etc... The voltage and current levels found here are MUCH lower, hence leaving them fired up is far more benign with less potential for major problems. Sean
Some tube equipment has a mode where only the filiaments are left energized, perhaps at slightly reduced voltage. It is always desirable to turn on filiaments before gradually bringing up plate voltage, but I don't know any audio amps that are this sophisticated.