H Day or H. Day may refer to:

• Dagen H (H Day), the day when traffic in Sweden switched to driving on the right
• H-dagurinn (H Day), the day when traffic in Iceland switched to driving on the right
• H. Day, a penal administrator of a convict settlement on Norfolk Island

• February 1915
• February 1917 Revolution
• February 19, 2017
• February 1933 lunar eclipse
• February 1936
• February 1937
• February 1937 Iraqi parliamentary election
• February 1938
• February 1943 lunar eclipse
• February 1944
• February 1944 lunar eclipse
• February 1950 tornado outbreak
• February 1953
• February 1954
• February 1955
• February 1956
• February 1958
• February 1968
• February 1969
• February 1974 Dissolution Honours
• February 1974 general election (disambiguation)
• February 1974 United Kingdom general election in Northern Ireland
• February 1976
• February 1985 Paris bombing
• February 1997 deaths