Coding Event Data

"Woman has used foam/jelly/cream for a unknown period beginning &ending sometime in 1980."


.EV 65 20 2 1 1 1980  31 12 1980 95 1980 0  Earliest possible starts 
.EV 65 21 2 2 1 1980  1 1 1981 95 1981 0    Latest possible ends

The START event code defines the earliest and latest possible dates on
which that START event could have occurred.  The END event code defines
that earliest and latest possible dates on which the END event could have
occurred.

START event 1980          [-----------------------------------]
END event   1980           [-----------------------------------]

START event June 1980                   [----]
END event   July 1980                        [----]

START event June 1 1980                 [-]
END event   July 15 1980                       [-]

START event June 1 1980                 [-]
END event   July ?? 1980                     [----]