Here is a timeline of the references to "message of necessity" in our New York State Budget process
See http://civic-data.github.io/laws-of-planet-earth/us/ny/scripts_openlegislation/getdata1.html for live chart and data.
It appears that "message of necessity" letters are being used mostly end of March 2015 and also June 2014. The outlier references in January 2015 seem to be attempts to stop the "message of necessity" usage by the current minority party in the New York State Senate and Assembly.
This tool can be used to search on any term and to chart on a timeline when it is used.
You can fork it on github here: https://github.com/civic-data/laws-of-planet-earth