Given Google Sheet date serial and a target date (election?) calculate difference in years

yearcalculate.py

def calculate_age(dobstring, targetdate):
    import datetime
    # Takes Google Sheets (Excel)-formatted date value, and YYYY-MM-DD formatted date.
    dobobject = datetime.datetime(1899, 12, 30) + datetime.timedelta(days=dobstring)
    # print(dobobject)
    targetobject = datetime.datetime.strptime(targetdate, "%Y-%m-%d")
    years = targetobject.year - dobobject.year
    if targetobject.month < dobobject.month or (targetobject.month == dobobject.month and targetobject.day < dobobject.day):
        years -= 1
    return(years)