For important events to manifest it should be seen from many indications in the chart, not just one, which collectively reveal a repeated pattern. For instance, the mahadasha of Venus, the significator of 7th house of relationship, is one indication for the start of a new relationship. However, this just sets a general trend over a long twenty year span. If the person also happens to be running the sub-period of the 7th lord, or a planet in the 7th house, while Jupiter is transiting in the 7th house then a pattern begins to emerge pointing toward the event happening.
The following chart is another example, like yesterday's chart, of a woman beginning a new relationship. She was running Jupiter-Moon-Venus on June 17th, 2003 when she started a new relationship. Notice, in her natal chart, that Jupiter, the mahadasha lord is in her 7th house. The Moon, the sub period lord, is the 7th lord in both the natal chart and navamsha. Venus, the sub sub period lord, is the 5th lord of romance, aspects the 7th house, and mutually aspects Jupiter. Venus, as mentioned, is also the significator of relationship in anyone's chart. This sets the stage for the event of a new relationship to be triggered. The transit of Jupiter, the mahadasha lord, through the 7th house further reinforces the likelihood of the event. Venus also was transiting through the 5th house of romance, on the day they met, conjunct the 7th lord Moon, while the Moon was transiting the 1st house conjunct Venus.
Transits on June 17, 2003