Your NexStar GT or GTL alignment procedures will prompt you for location and time at the beginning of every observing session. You will need to enter everything the first time you do it. Subsequent alignments (including those after you turn the scope off and on again) will give the last entered information with an option to correct the entries.
After you have chosen your alignment method, the hand control will display City Database. Many US cities and international cities are in the database. A city within 50 miles is usually more than sufficiently accurate for most amateur astronomy. Use the Up and Down keys if you want to select Custom Site to enter coordinates for a specific latitude and longitude. You can obtain your coordinates from maps, a handheld GPS, a phone with GPS or Google Earth.
Time is entered after the location and is also prompted. You can input either 24 hour military time or local time. If you enter a local time, such as 8:53, you will be asked to select AM or PM as the next step.
Pressing Undo at any step lets you change the values in case of an error.
The next time the scope is aligned, the last entered time and location are automatically displayed. Pressing Undo at the prompt allows you to go through and change any or all of the location and time information.