YearlyFourier.get_default_start_date

YearlyFourier.get_default_start_date(start_date=None)

Get the start date for the Fourier curve.

If start_date is provided, validate its type. Otherwise, provide the default start date based on the subclass implementation.

Parameters:

start_datestr or datetime.datetime, optional

Provided start date. Can be a string or a datetime object.

Returns:

str or datetime.datetime

The validated start date.

Raises:

TypeError

If start_date is neither a string nor a datetime object.