That's a great question ANNJON76, and we're here to help. I know how important it is for your kids to get a good night sleep without any temptation to use their phones during the night.
As your fellow community member mentioned, you can add Family Base to the account so you can set time restrictions on their phone. Visit http://vz.to/2btUTGI to view a video on how to set a restriction. We're here if you need further assistance.
Follow us on Twitter @VZWSupport
If my response answered your question please click the "Correct Answer" button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!
Aside from the Family Base option mentioned above, I don't think that will block wifi from the phone which would still allow internet and messaging depending on the platform.
Take the devices away from them at least 2 hours before bed time. This would be a good habit to get into now before school actually starts. The blue light from the screens will disrupt circadian rhythm and make it harder for them to fall asleep and sleep well. Give them a book instead.