Hi,

There is no GootTillTime parameter in the order.Close function, as for engine.Submit.

What's the best practice to manage a GootTillTime while closing order ?

Thanks

First of all - goodTillTime is used only with PLACE_BID and PLACE_OFFER, see:
https://www.dukascopy.com/client/javadoc/com/dukascopy/api/IEngine.html#submitOrder(java.lang.String,%20com.dukascopy.api.Instrument,%20com.dukascopy.api.IEngine.OrderCommand,%20double,%20double,%20double,%20double,%20double,%20long,%20java.lang.String)
Second - order close is either unconditional (IOrder.close()) or with price condition (IOrder.close(double price)), hence there is no time condition applicable for order close action. However you can implement this in your strategy by making a conditional order in opposite direction at a certain price and if it does not get filled in certain time then cancel the order, otherwise once the opposite-order gets filled, merge it with the original order. Find more explanations and examples here:
https://www.dukascopy.com/wiki/#Orders_overview