The exact time for the Spring (or Vernal) equinox 2011 is March 20th, 23.21 UCT. The sunset on the 20th is at 6.13pm and the sunrise on the 21th of March at 6.02am.
English Heritage did not confirm the date for Open Access for Stonehenge for the Spring Equinox 2011 yet, but most likely this will be dawn on the 21th of March.
Expect a short period of access, from approximately 5.45am to 8.00am.
