In spite of numerous attempts over the last 60 years to determine the 87Rb half-life and decay constant, there is still no consensus on the absolute values. Even the more accurate determinations of the last 30 years have resulted in discrepancies. Determinations based on comparisons of ages of earth minerals and rocks give two different values of the 87Rb half-life and decay constant to the values using determinations based on comparison of ages of meteorites and lunar rocks. Yet the most recent direct counting and in-growth experimental determinations only agree with the most recent determinations based on comparison of the Rb-Sr ages of earth minerals and rocks with their U-Pb "gold standard" ages. This has resulted in suggested values of the 87Rb half-life and decay constant that are different from the two values of each previously championed in the literature. A similar discrepancy in determinations of the 176Lu half-life and decay constant has been recognized in the literature, as well as variations in the 238U/235U ratio so critical to the U-Pb "gold standard" against which the Rb-Sr ages have been calibrated. Since the 87Rb decay rate has thus not been accurately determined, the Rb-Sr dating method is certainly not absolute and therefore cannot be used to discredit the young-earth creationist timescale. However, further study is warranted to explore any potential significance in this discrepancy in half-lives and decay constants between earth materials, and meteorites and lunar rocks.