A more thorough explanation:

Definition: The alternate valuation date is a tax law term that refers to the date six months after a person's death. The estate can choose to appraise the deceased person's property either as of the date of their death or as of the alternate valuation date.

Example: If a person dies on January 1st, their estate can choose to value their property as of January 1st or as of the alternate valuation date, which would be July 1st.

This term is important for tax purposes because it affects the basis of the property. Basis is the value assigned to a taxpayer's investment in property and is used to calculate gain or loss from a transfer of the property. The basis can be adjusted by capital improvements and depreciation deductions. The stepped-up basis is the basis of property transferred by inheritance and equals the fair market value of the property on the date of the decedent's death or the alternate valuation date.

Example: If a person inherits a house from their grandmother, the stepped-up basis would be the fair market value of the house on the date of their grandmother's death or the alternate valuation date, whichever is chosen by the estate.

Overall, the alternate valuation date is an important consideration for estates when determining the value of property for tax purposes.