#!/usr/bin/env ruby
#
# Define window start/stop times
...

def self.at_beginning_of_interval(time, interval_type)
      #simple substraction does not (seem) to work for long intervals (summer/winter time ?)
      #and at_beginning_of_hour is not defined
...

# Syncronize it
# Version 0.1
# Author : kyzh@snibbits.net
...

def date(date, time = false)
    date = Date.parse(date) if date.is_a? String
    day = date.strftime('%d')
...