When did the war start? 

The lead says it started 20 March 2003 but later in the article it says "At 9:34 PM EST (5:34 AM Baghdad time) on March 19, 2003 the Iraq Invasion began." with a citation of the GlobalSecurity website (the actual webpage is here). Then, later in the same section, it goes back to "In the invasion phase of the war (March 20-April 30)". Which one goes and which one stays? Is there a reason to doubt the GlobalSecurity site? I'm hearing a lot about today being the anniversary of the invasion and then I check here and it says the 20th, what should we do?