Online maintenance is the necessary evil of any service that requires an internet connection. Nintendo is not exempt, and is planning on starting a three-part  tonight/tomorrow. There are three blocks all together. It’s not a promise that the network will be completely down in these times, but if you wanted to do some ranked play in Smash or Splatoon, maybe try and schedule around it to be safe.

The Maintenance schedule is below:

North America (Pacific Time):
– [Switch/Wii U/3DS] January 23: 5:00pm – 8:00pm
– [Switch] January 23: 9:30pm – January 24 12:30am
– [Switch] January 27: 4:50pm – 6:30pm

Europe (CET):
– [Switch/Wii U/3DS] January 24: 2:00am – 5:00am
– [Switch] January 24: 6:30am – 9:30am
-[Switch] January 28: 1:50am – 3:30am 

Hopefully the impact will be minimal! In either case, stay safe out there on the internet.