I saw this today on the ESO support page, don't know if this had been linked earlier: https://help.elderscrollsonline.com/app/answers/detail/a_id/4839/kw/early%20access
And the Text:
WHEN WILL EARLY ACCESS BEGIN?
The five-day early access bonus that comes with pre-purchasing the digital Imperial and Standard Edition of The Elder Scrolls Online via our Online Store, as well as the pre-order of the physical Imperial Edition and digital Imperial Edition via third party retailers, will begin on March 30, 2014.
The three-day early access bonus that comes with pre-ordering the Physical or Digital Standard Edition of The Elder Scrolls Online will begin on April 1, 2014.
More specifically, the following locations, dates, and times for the five-day early access are:
North America (East): 7:00 AM EDT, Sunday March 30th
UK/IE: 12:00 PM WEST, Sunday March 30th
Central Europe: 1:00 PM CEST, Sunday March 30th
Sydney, Australia: 10:00 PM AEDT, Sunday March 30th
Singapore: 7:00 PM SGT, Sunday March 30th
The following locations, dates, and times for the three-day early accessare:
North America (East): 7:00 AM EDT, Tuesday April 1st
UK/IE: 12:00 PM WEST, Tuesday April 1st
Central Europe: 1:00 PM CEST, Tuesday April 1st
Sydney, Australia: 10:00 PM AEDT, Tuesday April 1st
Singapore: 7:00 PM SGT, Tuesday April 1st
Sorry if this is a re-post of information published elsewhere on this site.