Productivity improvement today can occur so fast "over time" means week to week.
Did you see how fast GM had to shut down operations? There's a reason their vehicles weren't selling and it went way beyond availability of credit ~ and to the very heart of the question of what productivity improvement has to do with the way our economy works. Ya' really gotta' produce something more than chick cars and SUVs to stay in business.
The time element in Austrian theory pertains to the observation that goods in the present are always more valuable than the same goods in the future. It's the basis of Boem-Bawerk's famous refutation of Marx's labor theory of value published back in the 1880's. It explains the existence of interest rates.