def METHOD_NAME(whatchanged_output):
    """
    Returns a generator of tuples of data parsed from
    "git whatchanged --pretty='TIME:%at". The tuples are of the form
    ``(filename, last_commit_datetime)``
    Sample input::
        ['TIME:1366884020', '',
         ':000000 100644 0000000... 5862ced... A\tlib/iris/cube.py']
    """
    dt = None
    for line in whatchanged_output:
        if not line.strip():
            continue
        elif line.startswith('TIME:'):
            dt = datetime.fromtimestamp(int(line[5:]))
        else:
            # Non blank, non date, line -> must be the lines
            # containing the file info.
            fname = ' '.join(line.split('\t')[1:])
            yield fname, dt