is there a less hacky way to create dynamic defaults for parameters as opposed to doing something like this?

@task(name="set-date-params", nout=2)
def set_date_params(
        start_date: typing.Optional[str],
        end_date: typing.Optional[str]
) -> typing.Tuple[datetime.date, datetime.date]:
    """
    If start date and end date are explicitly set on the Flow, we simply construct date objects and return them.

    If start_date is not set, we default it to 7 days from the local context date of the flow.

    If end_date is not set, we default it to the local context date of the flow.
    """
    context_run_datetime = context.get("date")
    aware_utc_run_datetime = context_run_datetime.replace(tzinfo=utc)
    aware_et_run_datetime = aware_utc_run_datetime.astimezone(et)

    if not start_date:
        seven_days_ago = aware_et_run_datetime - datetime.timedelta(days=7)
        start_date = seven_days_ago.date().isoformat()

    if not end_date:
        end_date = aware_et_run_datetime.date().isoformat()

    <http://logger.info|logger.info>(f"start_date={start_date}, end_date={end_date}")
    return datetime.date.fromisoformat(start_date), datetime.date.fromisoformat(end_date)


with flow:
    start_date_, end_date_ = Parameter("start-date", default=None), Parameter("end-date", default=None)
    start_date_, end_date_ = set_date_params(start_date_, end_date_)

Hey @Zach Schumacher, I don’t think there is anything better than what you have here, especially with the if logic and handling dates. A lot of users run into problems with default dates as Parameters because of the serialization fixing that value, so we recommend a setup like the one you have here.

i figured, just wanted to make sure i wasn’t missing anything. thx @Kevin Kho!