import datetime
import time


def to_datetime(datetime_string, format='%Y-%m-%d %H:%M:%S'):
    """Turn a date/time string into a datetime object."""
    return datetime.datetime.fromtimestamp(
        time.mktime(time.strptime(datetime_string, format)))

def to_date(date_string, format='%Y-%m-%d'):
    """Turn a date string into a date object."""
    return datetime.date.fromtimestamp(
        time.mktime(time.strptime(date_string, format)))


# Or, as of Python 2.5:

from datetime import datetime


def to_datetime(datetime_string, format='%Y-%m-%d %H:%M:%S'):
    """Turn a date/time string into a datetime object."""
    return datetime.strptime(datetime_string, format)

def to_date(date_string, format='%Y-%m-%d'):
    """Turn a date string into a date object."""
    return to_datetime(date_string, format).date()