The Division servers will be down on Friday 13th of January because of deploying a fix.
On this day (when usually bad things happen for most of the people), Ubisoft decided to deploy a fix in order to prevent the WarrenGate power Plant farming exploit.
Also, players could’ve experience very quickly by resetting missions, so because of that, a cooldown will be added when resetting missions multiple times.
This farming exploit was allowing people to get Field Proficiency Caches, a lot of them for a fast period of time without sweating at all.
The upcoming patch will keep the servers down for around 3 hours and they will shut down more precisely at 00:30 AM PST / 03:30 AM EST and 09:30 CET.
This was announced on Ubisoft’s forum and you can find the full changelog on this link.