There are a couple of things to do before setting play time limits. Please check if you are ready before proceeding to the following
Preparation
Nintendo Switch Parental Controls is a mobile app designed for parents and guardians to monitor their child’s game play. You can manage gameplay time and adjust restrictions based on the games age-rating and communications features.
Restricting age-inappropriate games can also be done from the Nintendo Switch console (However, you cannot set different restrictions on a per-game basis in this way).
Select "Console Settings" from within Nintendo Switch Parental Controls and then "Restriction Level."
Selecting "Teen, Pre-Teen, or Child" from within "Restriction Level" will restrict the games that can be played to only those that are age appropriate.
Games with the following ratings will be restricted for age groups below:
17+ for Teens, 13+ for Children, 8+ for Young Children.
If you have multiple children sharing the same Nintendo Switch system, you should set the Restriction Level with the youngest player in your home.
You may add games with which you feel comfortable to a "Whitelist". First, go to "Console Settings". Then go to "Whitelist" and select the game title. Be sure to hit "Save" at the top right of the screen when you are finished.
Age restrictions apply to everyone using the same Nintendo Switch system. If some family members do not require parental controls, hit the orange button at the top of the Nintendo Switch HOME Menu screen and enter your PIN to temporarily disable them.
The restrictions can be activated again by pressing the button that is in the “OFF” state.
Once the Nintendo Switch system enters sleep mode, the restrictions will automatically be activated again.
You may view and change your PIN from within the Nintendo Switch Parental Controls app by going to "Console Settings" and selecting "PIN". Please be sure not to share this PIN with your child.