The [index] section of a configuration file contains options used to determine the start and end years of climate indices (such as El Niño 3.4):

## options related to producing nino index.

# start and end years for the nino 3.4 analysis.  Using out-of-bounds values
#   like start_year = 1 and end_year = 9999 will be clipped to the valid range
#   of years, and is a good way of insuring that all values are used.
# For valid statistics, index times should include at least 30 years
startYear = 1
endYear = 9999

Start and End Year

A custom config file should specify a start and end year for climate indices. If the end year is beyond the range of the simulation (typically true for the default endYear = 9999), the range will be reduced to those dates with available data and a warning message will be displayed.