Deductions & credits

I have been trying to research this question about electing a FYE for Estates and cannot find anything definitive.  The question is: What is considered the "initial" year return.  I often have situations that don't require a tax return for several years until a piece of real estate is sold.  So, for example, if the DOD is say, 4/25/2018 but a return is not required until something is sold on, say, 7/15/2020, can I elect an FYE 3/31/21 since no return would be required for FYE 3/31/19 or 3/31/20?