I have forked one of the app's released on GitHub by Fairphone/Kwamecorp, the Peace of Mind app. It's bascially an Airplane Mode with a timer.
We become more conscious of our phones as our lives become increasingly connected. Would you like to disconnect, if only for a moment? Your phone will go silent and disconnect from the world: no e-mail, no status updates, no SMS and no phone calls. Choose how long you wish to disconnect (up to 12 hours).
Released under the Apache License version 2.0. Source code and APK are available here https://github.com/mudar/Fairphone
For Android 4.2+ devices, the app requiers Root privileges to enable the Airplane Mode. On non-rooted phones (or if SU is declined) the app enables Silent Mode instead. This is due to security changes introduced by Google in Android SDK version 17.
Attached are two screen captures and the APK.
Read article on XDA's portal

Put Airplane Mode on a Schedule with Peace of Mind+ by @willverduzco
Download:
Check GitHub for the lastest version and version release history
Changelog:
versionCode=18 versionName=2.1.0
- Updated to Material Design
- Added support for Android's "Do not disturb" mode
- Optimizations, clean animation, etc..
- Airplane mode support for rooted devices
versionCode=12 versionName=1.2
- Restore sound to previous setting (bug fix)
- RootTools updated to version 3.4
versionCode=10 versionName=1.1
- Enhanced tablet layout
- Fixed bug for some Android 4.3 devices
versionCode=8 versionName=1.0
- Out of beta!
- Improved Widget layout
- DashClock extension added
- Restores previous ringerMode at the end of an Airplane-mode PeaceOfMind
- Added About dialog (in Settings)
- Added Brazilian-Portuguese and Russian translations, and completed other translations