Iphone 6 - problem with the alarm

The alarm on my Iphone 6 used to work even if the phone was off, but suddenly it won’t. I don’t like to leave the phone on at night for a number of reasons. Have combed through the settings but can’t find anything - and I know I never intentionally changed it. Anyone know what gives?

If an iPhone is “off”, it’s off and nothing works. Just like a tv, or car, or computer, or toaster…

Try setting it to “airplane” mode at night.

If an iPhone is “off”, it’s off and nothing works. Just like a tv, or car, or computer, or toaster…

Try setting it to “airplane” mode at night.[/quote]

But yet… This is a recent development. I’ve always turned it off at night, and the alarm has always woke me up in the morning. I don’t think I hallucinated this memory. Moreover, every phone I’ve ever had has had the same ability to turn itself on to give me a morning alarm - which is no surprise, since they’ve all got batteries in them.