What is considered a Trading Day?
Updated
A trading day runs from 5 PM EST to 5 PM EST.
A day is counted as a trading day when you close at least one position during it and the minimum daily profit requirement for your model and phase is met. Opening a trade without closing it does not count.
Where a profit requirement applies, the day must close with a profit of at least 0.5% of the initial account balance, net of fees and commissions. These days are called minimum profitable days.
The number of days required for each model is listed in What are the Minimum Profitable Days?