Here are the two profiles you'll need (
Sleep Mode &
Sleep Mode Emergency). Let me know if they import into Tasker OK. Never exported/imported before. I can do it differently (screenshots or something) if this doesn't work.
Edit: Here's how to import them, in case anyone is confused
1.) On your device, click on the the two XML files above and download them to your device (they'll be in the "download" folder).
2.) Launch Tasker on your device
3.) Long press on the "Profiles" tab along the top
4.) Select "Import"
5.) Using the carrot icon on the right, navigate to your "download" folder
6.) Select the first xml file, and import it.
7.) Repeat the process above for the second xml file
8.) Make sure they're enabled in Tasker
9.) Modify the scripts to fit your needs. They're initially set for 12 am on and 7 am off, and to allow all calls. You can change the times and add specific numbers to allow (use the magnifying glass to select contacts).