iPhone 6+ can we turn off phone, but still have alarm clock work?

[pleasehelp1]

Regarding an iPhone 6+, My BF owns this phone and is tech-oriented, but can’t figure the following out. If you could be specific that would really help. Thanks so much.

How does he turn off his phone before sleeping so it won’t wake us up, yet still have his phone's alarm clock features work? If he has to set an alarm, he’s been leaving the phone on, which interrupts sleep. (Note: he chooses to not set up voicemail at this time - I don’t know if that’s needed info to answer my question.)

 

[adrianlondon]

Put phone in Airplane mode overnight.

If it's off, it's off. No alarms will work.

 

[casperes1996]

Alternative to the above - setup bedtime schedules or Do Not Disturb

 

[Mr.Blacky]

What did he tried already?

 

[BugeyeSTI]

Get a dedicated alarm clock. If he turns his phone off, no alarm..