Still the same case, I really appreciate the insights by this community and it helped me tremendously to work on the case.  I am again stuck with some confusion with regards to the Section 645 election.  Worrying about the election, if made, ended up invalid, I'm hoping to borrow your brain to understand the election period and applicable date correctly. 

Facts summary: 

• The Qualified Revocable Trust is a husband-and-wife joint living grantor trust. 
• Husband died in August 16, 2019, survived by wife. 
• No estate EIN applied subsequent to the death.
• The QRT (Qualified Revocable Trust) needs to file its first Income Tax return for year 2021, with a Florida deadline which is 2/13/2023. 
• The trust's taxable income was generated in October and December, 2021, with two major appreciated asset disposals. 

Actions I plan to take:

• Apply for a EIN for the late husband Estate, for the purpose of "related estate" for the Sec. 645 election.
• Report the revocable trusts' income that is attribute to the decedent on Form 1041, and report the income attribute to the surviving wife on her Form 1040.  
• With Form 1041, I'll attach Form 8855 obtaining executors' approval to be treated as part of the decedent' estate.  Now the election period questions arises: 

Confusion starts here: 

Per the Form 8855 instruction, the Section 645 election needs to be made by the deadline (including extension) of the first Form 1041 filing deadline, which is 2/13/2023.  We are good on that.  

The "Applicable Date" needs to be after two years after the husband's death. If the two year clock starts from the actual date, 08/16/2019, the taxable transactions then fell out of the two year period. But should the clock starts from 12/31/2019, the last day of the year of death?  

Question: 

What does the "election period" govern?  Does that govern the validity of Sec. 645 election, or does that govern that the QRT has to be treated as an irrevocable trust within this two year period? 

Am I correct to think: 

1. the Sec. 645 election is still timely made, thus valid;
2. As the two year election period has passed from 12/31/2023, the QRT should be continuously treated as a revocable trust from the 2022 tax year?  

Thank you again!!