class ICalPal::Event

def apply_frequency!
  # Leave edate alone for birthdays to compute age
  dates = [ 'sdate' ]
  dates << 'edate' unless self['calendar'].include?('Birthday')
  dates.each do |d|
    case EventKit::EKRecurrenceFrequency[self['frequency'] - 1]
    when 'daily'   then self[d] +=  self['interval']
    when 'weekly'  then self[d] +=  self['interval'] * 7
    when 'monthly' then self[d] >>= self['interval']
    when 'yearly'  then self[d] >>= self['interval'] * 12
    else $log.error("Unknown frequency: #{self['frequency']}")
    end
  end
end