Planning tools are designed to assist the user with decisions around start and stop times for a specific target.
Reading the graph
Day and night: Any bluish area represents daylight and any blue to black gradient represents twilight. The black area is always suitable for imaging. Twilight is rendered using "Amateur Astronomical Twilight" (-15 degrees).
Altitude: The orange series represents a targets altitude over time (for the current night). This sample shows a target that is only at 20 degrees when twilight is over... not a suitable target.
Horizon: The horizon is a user defined value that represents your (artificial) horizon. The initial value here will be derived from the horizon value found in the user profile you are using. This value can help you visually identify appropriate start and end times. If you change the value here, it will only be saved as part of the current sequence and will not change the value found in the user profile. The sample above shows an artificial horizon at 45 degrees.
Using the graph
When you hover the mouse over the graph, it will show a vertical red line that is indicative of the position (time). If you left click anywhere there, it will set the target start time to the value shown in the "Cursor" time field (indicated by a green dot). Right clicking will do the same for the target's end time (indicated by a red X). Note: This functionality does not work unless the "Start at" and "End at" checkboxes are actually check (in target settings).
Transit: Below the "Cursor" information, information for the target's nearest transit is displayed. This indicates when the target will start to decrease its altitude and head toward the horizon.
Solar / lunar data: Next to the "Cursor" and "Transit" information area, there will be general information about the sun and moon for the current night. Dusk and dawn are calculated using "Amateur Astronomical Twilight" (-15 degrees).
Errors: If SGPro has detected errors in the values you have chosen or is unable to render parts of the graph, it will tell you why here (Note, the most common issue encountered is that the planning tools do not render anything because they do not know your location on earth... click the link at the bottom of the planning tools to correct).
Warning: Much like errors, except SGPro is not certain if you meant to do that or not.