Can o take diazepam (valium) for sleeping?

Not good idea: Sleeping pills should only be taken here and there, now and then, not everyday for weeks/months/years. Sleeping pills should be effective through the night and stop working by morning, which means they should have short half-lives. Diazepam has a 20-100 hour half-life, so it is still in your system all day the next day and is not a good idea as a sleeping pill.