According to an old revision of Wikipedia:
On January 19, 2025, Leonard Peltier's sentence was commuted to indefinite house arrest by President Joe Biden shortly before he left office. He is scheduled to be released from prison on February 18, 2025.
If Peltier has his sentence commuted on Jan 19, 2025, how can the prison "take" another month of his life, to release him? Does a prison have a right to detain you after your sentence has been commuted?
The Executive Grant of Clemency says:
I HEREBY COMMUTE the remainder of the total sentence of imprisonment imposed upon LEONARD PELTIER, Reg. No. 89637-132, to be served in its entirety on home confinement, to take effect on February 18, 2025. I leave intact all other components of the sentence.
There is no delay between the effective date and the transfer to home confinement.
And this cannot be undone. What becomes effective on February 18 is the alteration of the mode of confinement. The grant of clemency itself was "done... this 19th day of January in the year of our Lord Two Thousand and Twenty-Five and of the Independence of the United States the Two Hundred and Forty-Ninth." As an analogy to property law, this is like a vested right to a future interest.