The Wikimedia Technical department is doing a major test for a new data center. This work will improve the reliability of the servers and their ability to recover from a major disaster.  As part of this work, it will briefly be necessary to put all of the wikis into read-only mode.  This will make it impossible to edit or save any page on Wikipedia or any related project, including the Outreach wiki, during those times.  

The current schedule [1] is this:

* No editing for 5 minutes on Tuesday, 15 March at 07:00 UTC (3:00 a.m. EDT)

* No editing for 15 to 30 minutes on Tuesday, 22 March

The exact time for the second and third events has not been determined.  It will be posted at [1].  It will probably be during a low-traffic time such as 7:00 UTC. 

I am sending this information to these lists because being unable to edit would obviously be very disruptive to any training classes or edit-a-thons.  I apologize for the late notice.  I hope that this will not interfere with any of your work.  

There is more information posted here:  https://meta.wikimedia.org/wiki/Tech/Server_switch_2016  If you have questions for me, then please contact me on wiki at https://en.wikipedia.org/wiki/User_talk:Whatamidoing_(WMF)

[1] https://wikitech.wikimedia.org/wiki/Switch_Datacenter#Schedule_for_Q3_FY2015-2016_rollout