In a livestream from Benghazi.According to Bloomberg she leased the campaign headquarters on April 1 (which would support an earlier Guardian
article that this was the date pencilled in to be the operational start date for the campaign). If that's the case she has till April 16 to announce by FEC rules. Even if this weren't the case I can't see her announcing later that April 20: her team will want to optimise this fundraising quarter.
I'll predict April 14: Equal Pay Day is better symbolism than Tax Day.
Surprise tweet/video followed by an Upstate New York announcement (in Seneca if she wants to go really bold) and immediate trips to Iowa and New Hampshire.
