As a disciplined trader if a trade has been executed with the perspective of closing it on the same day it should be religiously followed and the trade should be closed on the same day before the close of the market even if it ends in a loss.
In some cases the Intraday trader uses the margin amount provided by the brokers to trade in the market, any transaction that is done using the margin amount has to be closed before the close of the market.
In Intraday trading any short position created has to be exited or bought back before the close of the same day.
In a scenario where the stock is bought in the intention of closing it on the same day with sufficient fund in the account it is not mandate to exit the trade even the intention of buying the stock was for Intraday position, however in scenario’s like using brokers margin amount or creating a short position it is mandate to close / exit the position.