12/24/2011
https://www.presidency.ucsb.edu...
"This order is effective at 1:00 p.m. eastern daylight time on May 18, 2011."
"I have issued an Executive Order that takes additional steps with respect to the Government of Syria's continuous escalation of violence against the people of Syria."
"all parties must refrain from violence"
"The Secretary of the Treasury, in consultation with the Secretary of State, is hereby authorized to take such actions..."