Nintendo will conduct maintenance for the 3DS' online network next week, the company has announced. On January 9, some network services may become unavailable, including online __play and rankings, Nintendo said in an official support statement (via DualShockers).
The maintenance period begins on January 9 at 5 PM PT and is scheduled to run for two hours, ending at 7 PM PT. That comes out to 8 PM - 10 PM ET and 1 AM - 3 AM UK time on January 10.
This appears to be regular maintenance and not anything out of the ordinary.
In other Nintendo news, the company's marquee Nintendo Switch briefing is scheduled for the evening of January 12. During this, Nintendo is expected to announce the console's price and launch lineup, and also provide more specifics about the hybrid system's specs. Keep checking back with GameSpot for the latest.