Hold a seat reservation means that you keep a seat to yourself for some limited time as the airlines do not allow passengers to hold the ticket for much time. It is best to keep your seat reservation on hold if you are not sure about your trip but at the same time, you don't want to lose the seat.
The maximum hold time that many airlines have is 24 hours. Few airlines have policies to allow their customers to hold their flight for more than 24 hours. There are few airlines that do not charge you anything for 24 hours but charge you the extended hold charges. There are few airlines that charge for the hold reservation fee and along with that if the customer is willing to extend their hold then charge for the extension as well.
The airlines do not give the hold reservation for a long time because it might be possible that you do not book your ticket then the airlines can lose their potential customers. So the answer to CAN YOU HOLD A FLIGHT RESERVATION? is YES.
If you want to book your flight then you can but if you do not want to book any flight ticket so you can leave as it is. It will be automatically canceled after your time express.