calculates the number of days to be forwarded based on year and month (adjust-days {:years 0 :months 2} {:year 2012 :month 1 :day 31}) => 60

(adjust-days {:years 1 :months 2} {:year 2012 :month 1 :day 31}) => 425

(adjust-days {:months 2} {:year 2012 :month 1 :day 31 :backward true}) => 62

(adjust-days {:years 1} {:year 2013 :month 1 :day 31 :backward true}) => 366

calculates the number of days to be adjusted based on month (adjust-month-days 0 2 {:year 2012 :month 3 :day 1}) => 61

(adjust-month-days 0 2 {:year 2012 :month 3 :day 1 :backward true}) => 60

(adjust-month-days 1 2 {:year 2011 :month 1 :day 3}) => 60

(adjust-month-days 1 2 {:year 2012 :month 1 :day 3}) => 59

calculates the number of days to be adjusted based on year (adjust-year-days 1 {:year 2012 :month 2 :day 28}) => 366

(adjust-year-days 1 {:year 2012 :month 2 :day 29}) => 365

(adjust-year-days 1 {:year 2012 :month 3 :day 1}) => 365

(adjust-year-days 1 {:year 2011 :month 3 :day 1}) => 366

converts a duration to a length (map-to-length {:months 2} {:year 2012 :month 1 :day 31 :backward true}) => 5356800000

converts a duration map to a duration in milliseconds (to-fixed-length {:days 1 :hours 3}) => 97200000

(to-fixed-length {:weeks 2 :days 7 :hours 53}) => 2005200000