The range of years displayed in the year drop-down: either relative to today's year (-nn:+nn), relative to the currently selected year (c-nn:c+nn), absolute (nnnn:nnnn), or combinations of these formats (nnnn:-nn). Note that this option only affects what appears in the drop-down, to restrict which dates may be selected use the minDate and/or maxDate options.
+/1 10 selected year
c-nn:c+nn: Where nn is the number of years (range relative to selected year)
-nn:+nn: Range relative to current year.
nnnn:nnnn: Absolute years.
c-2:c+2: Range of two years around selected year
-1:+3: From one year ago to 3 years ahead
2000:2050: Range from years 2000 to 2050