fair enough, i was envisioning setting up the target in the afternoon or early evening and wanting to know what time the target would clear my house.
however, since i would think of the time shown as only advisory, i didn't expect that it would prevent the target from running if i were setting it up while it was in the sky. after all as @DesertSky says these times have to be computed on the fly anyway, so as long as the horizon constraint was satisfied then the target should be eligible to run. that is, currently if the time is 11PM and i create a target with a start time of 10PM and then press "start", wouldn't SGP still run that target? i am thinking about this the same way - if i entered an elevation of 40 degrees and it reached 40 degrees at 10PM, then it would still be eligible to run when i clicked "start" at 11PM.
anyway, once i've set up a target, i pretty much don't care when it runs anymore. i will just know that it won't start until the target is visible, and will be able to start earlier and earlier each night automagically. the initial time that would be calculated and shown in the UI is basically just advisory. i'd still have to arrange the targets in order of RA, i assume, so that as the current one goes behind the tree, the list of next possible targets are all "legal", meaning have earlier RAs.