Absentee voting provides a means for qualified voters to participate in upcoming elections even though they may not be able to go to the polls on election day. Absentee voting in person begins approximately 45 days before a November General Election and approximately 30 days before other elections and ends  on the Saturday before the election

More information here -

http://www.sbe.virginia.gov/cms/Absentee_Voting/Index.html

- and here -

http://vote411.org/bytopicresult.php?state[]=VA&topic10=true