Round datetime to 5 minutes boundary:

    - if moment.minute < 5 -> moment.minute = 0
    - if moment.minute >= 5 -> moment.minute = 0

    :param moment: a :class:`datetime.datetime` instance.

def round_to_5_minutes(moment):
    '''Round datetime to 5 minutes boundary:

    - if moment.minute < 5 -> moment.minute = 0
    - if moment.minute >= 5 -> moment.minute = 0

    :param moment: a :class:`datetime.datetime` instance.
    '''
    return moment - timedelta(minutes=moment.minute % 5, seconds=moment.second)