締め日を指定して会計月度を取得

GetFiscalMonth.groovy

Date.metaClass.getFiscalMonth = { p ->
  cal = Calendar.getInstance();
  cal.setTime(delegate)
  if (cal.get(Calendar.DATE) > p) { cal.add(Calendar.MONTH, 1) }
  cal.set(Calendar.DATE, 1)
  cal.getTime()
}

Date.metaClass.toString = {
  delegate.format('yyyy/MM/dd')
}

def toDate = { Date.parse('yyyy/MM/dd', it) }

// Test
println toDate('2011/06/20').getFiscalMonth(20).toString()
println toDate('2011/06/21').getFiscalMonth(20).toString()
println toDate('2011/06/30').getFiscalMonth(99).toString()
println toDate('2011/07/01').getFiscalMonth(99).toString()