Had cash stolen in a fraud situation. Trying to fill our Form 4684. I know date of theft. How do I determine date acquired?

Casualty and Theft losses are not deductible on a federal tax return unless the loss occurred in a federally declared disaster area.

if it was a loss due to a PONZI scheme a special section of the 4684 needs to be completed but Turbotax does not handle PONZI losses.