There is no prescribed duration for the FTMO Challenge: 1-Step. The minimum duration required to pass FTMO Challenge: 1-Step depends on the applicable Trading Objectives.
For example, on a 10,000 USD FTMO Challenge: 1-Step:
Completing the evaluation in two trading days is only possible in a very exceptional case, where the trader achieves exactly 50% of the required profit on the first trading day and the remaining 50% on the second trading day, in order to comply with the Best Day Rule (50%), which limits the maximum profit contribution of a single trading day.
In practice, three trading days are considered the minimum standard, as achieving exactly 50% of the required profit within the Best Day Rule limit is highly specific and not a common scenario. In most cases, traders reach the Trading Objectives gradually over three or more trading days, while respecting risk management, trading consistency, and the Best Day Rule.