import datetime

def get_months_between(start_date: datetime.datetime, end_date: datetime.datetime) -> int:
    """
    Calculate number of months between two dates.
    """
    months = (end_date.year - start_date.year) * 12 + (end_date.month - start_date.month)
    # Add 1 to include both start and end months
    return months + 1