How to add months, days, years to a date in Groovy

groovy-date-time-operations

Groovy also has a Time Category class which gives you DSL style syntax for manipulating dates. Here is an example:

import org.codehaus.groovy.runtime.TimeCategory
now = new Date()
println now
use(TimeCategory) {
    footballPractice = now + 1.week - 4.days + 2.hours - 3.seconds
}
println footballPractice
which will produce output like this:

Sat Sep 27 10:00:12 EST 2008
Tue Sep 30 12:00:09 EST 2008

ref: http://groovycookbook.org/basic_types/dates_times/

use(TimeCategory){
dt1 = dt1 + b.year
dt1 = dt1 + c.month
}
Based on the above code - year is getting increased on the date dt1. But, months is not getting increased by c integer value. Also, there is not error message as well.