Thanks @reallyrehan

I think we can achieve this using relativedelta, as well, yeah?

from datetime import datetime
from dateutil.relativedelta import relativedelta

if not data["start_date"]:
    end_date_obj = datetime.strptime(end_date, "%Y-%m-%d")
    start_date_obj = end_date_obj - relativedelta(months=3)
    data["start_date"] = start_date_obj.strftime("%Y-%m-%d")

@virattt Originally, I used relativedelta, but realised dateutil doesn't come packaged as default with python - so calendar would be a better option to not add an additional package requirement

The relativedelta code is indeed much cleaner though! What would you suggest?

I think the relativedelta 3-line change is cleaner @reallyrehan