The most accurate method of assessing compatibility is the analysis of inter-aspects between charts, which is not very birth-time sensitive (with the exception of aspects to the angles in short ascension ascendant charts and, of course, aspects by the Moon if the birth time is completely uncertain), but rather depends on when each chart was created. An aspect is defined as two planets being within one degree of each other on the celestial sphere. So if the angle between Jupiter and Saturn is about five degrees, then they are said to be in an aspect. If there are no other factors involved, such as transiting planets or houses, then an aspect represents a period where one planet can have an impact on the other. As far as predicting future events based on current positions of the stars, this would depend on how long you want to look back in time. For example, if we were looking at reports from the time of Jesus' birth, then some types of aspects could be useful for predicting what year it was, but beyond that any interpretation of aspects as symbols is just guesswork. A more modern example might be reading omens in animal births or movements of the moon, which is also just guessing work. In both cases, people just like making up stories because it makes them feel powerful enough to know what will happen next in their lives.