Validity period for limit order
The limit order requires the validity period because it remains unclear whether filled or not. The most famous validity is the Day order and the GTC order. You can choose any way you like.
Day order is a kind of orders regarding to time limit. The day order should be working until the end of the day session. It is needless to say that the Day order won't work any more when the trade date changes. The forex market moves during 24 hours without rest, and then, the end of day session falls on the New York close when the Japanese are just awake.
GTC order : ( Good Till Canceled )
GTC order is a kind of orders regarding to time limit. This is the abbreviation of "Good Till Cancelled". As this abbreviation means, the GTC order should be left good until it is cancelled or the executed in the forex market. Take care of careless mistakes to forget to cancel GTC order after you take profit or cut loss.