My Engagement shoots typically last between 1-2 hours, but ultimately it really depends on several factors if this will be suitable for your specific session. This amount of time genrally allows for you to warm up, a few different feeling backdrops and an outfit change if desired. Your specific photographer can provide a more accurate timeframe based on your specific needs and vision for the shoot. If you're wanting to do something really epic though, you don't want to go to all the trouble of planning it and then have to rush through the actual session itself. Likewise, if you know you're going to be nervous and will need some time to warm up to the camera or for your photographer to really help you get comfortable posing, then book a longer session. Your photographer will probably have a standard session advertised, but this will be a guide, not a rule, so don't be afraid to ask their advice if you think you need longer or want a custom session. Just remember, this will be reflected in the price you will need to pay.