You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lock.rb
    path of file: ./repos/ice_cube/lib/ice_cube/validations
    
    the code of the file until where you have to start completion: module IceCube
  # This validation mixin is used by the various "fixed-time" (e.g. day,
  # day
    
    def validate_day_lock(time, start_time)
      days_in_month = TimeUtil.days_in_month(time)
      date = Date.new(time.year, time.month, time.day)

      if value && value < 0
        start = TimeUtil.day_of_month(value, date)
        month_overflow = days_in_month - TimeUtil.days_in_next_month(time)
      elsif value && value > 0
        start = value
        month_overflow = 0
      else
        start = TimeUtil.day_of_month(start_time.day, date)
        month_overflow = 0
      end