Emancipation Day (Regional) Calendar When: April 16, 2018 all-day 2018-04-16T00:00:00-05:00 2018-04-17T00:00:00-05:00 Where: USA Holiday Washington DC Only. Weekday closest to April 16th. Washington DC Only. Weekday closest to April 16. marks the abolition of slavery in the District of Columbia. A regional holiday in Washington DC. Information provided by www.officeholidays.com