Split date range by 'N' smaller ranges

split_date_range.rb

def recursively_split_dates(start_date, end_date, dates_array, num_days_to_add)
  if start_date >= end_date
    last_date = dates_array.pop

    dates_array << { start_date: last_date[:start_date], end_date: end_date }
  else

    start_date += num_days_to_add

    dates_array << { start_date: dates_array.last[:end_date] + 1.day,
                     end_date: dates_array.last[:end_date] + num_days_to_add } if start_date <= end_date

    recursively_split_dates(start_date, end_date, dates_array, num_days_to_add)
  end
end

def split_date_range(start_date, end_date, split_number)
  if 1 == split_number
    return [{start_date: start_date, end_date: end_date}]
  end

  num_days_to_add = ((end_date - start_date).to_i / split_number).days

  recursively_split_dates(start_date + num_days_to_add, end_date, [{start_date: start_date, end_date: start_date + num_days_to_add - 1.day}], num_days_to_add)
end

# ============= Example ================== #

start_date = Tue, 01 Mar 2016
end_date = Sun, 30 Apr 2017

# 1.
split_date_range(start_date, end_date, 2)
=> [
  [0] {
    :start_date => Tue, 01 Mar 2016,
      :end_date => Wed, 28 Sep 2016
  },
  [1] {
    :start_date => Thu, 29 Sep 2016,
      :end_date => Sun, 30 Apr 2017
  }
]

# 2.
split_date_range(start_date, end_date, 6)
=> [
  [0] {
    :start_date => Tue, 01 Mar 2016,
      :end_date => Mon, 09 May 2016
  },
  [1] {
    :start_date => Tue, 10 May 2016,
      :end_date => Mon, 18 Jul 2016
  },
  [2] {
    :start_date => Tue, 19 Jul 2016,
      :end_date => Mon, 26 Sep 2016
  },
  [3] {
    :start_date => Tue, 27 Sep 2016,
      :end_date => Mon, 05 Dec 2016
  },
  [4] {
    :start_date => Tue, 06 Dec 2016,
      :end_date => Mon, 13 Feb 2017
  },
  [5] {
    :start_date => Tue, 14 Feb 2017,
      :end_date => Sun, 30 Apr 2017
  }
]