Recession Start & End Dates
(from Wikipedia)

year start end
1948 NOV1948 OCT1949
1953 JUL1953 MAY1954
1957 AUG1957 APR1958
1960 APR1960 FEB1961
1969 DEC1969 NOV1970
1973 NOV1973 MAR1975
1980 JAN1980 JUL1980
1981 JUL1981 NOV1982
1990 JUL1990 MAR1991
2001 MAR2001 NOV2001
2007 DEC2007 JUN2009