As a beginner, I used to choose Day as the validity for ordering stocks. But there are other validity types that you can choose depending on the situation.
Using the PSE trading platform, here the ORDER VALIDITY TYPES (according to time/validity):
a. Day Order (DAY)
Day Order is valid until the end of the trading day only. If the investor’s buying or selling order is not matched during the day, this will automatically be cancelled and will have to be reposted by/for the investor on the next trading day.
b. Good Till Cancelled (GTC)
Good Till Cancelled is valid until cancelled by the investor or trader or until it has reached the set expiration date of the security.
c. Good Till Date (GTD)
Another most frequently used limit order is the Good Till Date which is valid until the date specified by the investor.
d. Good Till Week (GTW)
Good Till Week is a type of limit order which is valid for seven (7) calendar days. If unmatched within seven (7) calendar days, the buy or sell order will automatically be cancelled and will have to be reposted by the investor though his trader or through his online trading account.
e. Sliding Validity (SLIDING)
Sliding Validity Order is valid for 360 calendar days from the time it is posted.
f. Fill-and-Kill (FAK)
The Fill-and-Kill (FAK) Order, also referred to as ‘Execute-and-Eliminate Order’, is valid upon execution. Fill-and-Kill orders require the stockbroker to instantly execute a trade at the quoted market price. If the stockbroker is not capable of doing so, the order is immediately discarded.
Source : PSE Academy