Are LDC monitors suppose to be left on or off while not in use?

I have an LCD monitor that I have left on every day for the last 7 years. It does not use much electricity either. I leave it on as I like the screensaver changing pictures all the time as I have an extensive collection of screensavers. Doesn't hurt it one iota to leave on. It's your personal preference though if you wish to turn it off.