What is the reason for unmanaging them? Just so that you don't get alerted on issues? If that's the case, change the time details on your alerts to not alert you between the hours of 6pm - 6am.
But to unmanage your nodes, you will need to do this manually each day.
On the SolarWinds server, you will find an 'Unmanage scheduler' utility that you can use to define recurring unmanage schedules
- Remote access your Solarwinds Server
- Go to Start >> search >> Unmanage schedule utility
- Click Crete new task
- Click Add items >> select the node >> and hit add >> set the duration on how long the node will be unmanage. >> click ok
- Click Open Task Scheduler >> Click Create basic Task
- Put the name of the task and description >> Next
- Set on how frequent it will trigger (unmanage)
- Put the start date and time >> next
- Select start a program >> next
- On the Program/script >> put the script that you need to run this to unmanage the node >> browse the one you have created.