def _get_frequency_offset_alias(frequency):
    """Get pandas offset alias for given frequency."""

    if frequency == 'hourly':
        return '1H'

    if frequency == 'daily':
        return '1D'

    if frequency == 'monthly':
        return '1MS'

    if frequency == 'yearly':
        return '1A'

    return 'QS-DEC'