In the Python Prophet package, how can I pass the initial, period and horizon arguments as defined string variables instead of hard-coding the strings

Question

The function cross_validation(m, initial='365 days', period='180 days', horizon='365 days') works, but when I parameterize the arguments like this:

initial_days = '1456 days'
period_days = '28 days'
horizon_days = '84 days'

cross_validation(m, initial=initial_days, period=period_days, horizon=horizon_days)

the function no longer works the same and I get an error saying the seasonality is 365.25 days and I should increase my initial period.

I'd like to parameterize these values instead of hard-coding them into the function.

I've tried setting the arguments to None first and that didn't work. I've also tried using

initial_days = pd.to_timedelta('1456 days')
period_days = pd.to_timedelta('28 days')
horizon_days = pd.to_timedelta('84 days')

This gives me the same error and initial being less than 365.25 days.