All challenges officially begin once you place your first trade. For example, you can place your first trade 29 days after purchasing your challenge, which will begin your challenge.

All trading history is recorded (cancelled, pending, executed, etc). The trading period starts to count when the first trade transaction is placed, not on the first trade executed in the market. That is independent of the type of the order.
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Whether the trade is activated or not, once an order is placed, the trading time starts to count.