User blog comment:DemonicsFire/volume 4 and the "new" ages/@comment-14539881-20160711154217/@comment-26397825-20160712025948

The timeskip is less than twelve months, but it's been more than a year since V1 started. If we count Red Trailer as the beginning, that was in Winter as there was snow on the ground. From the Red Trailer to the end of V3 is a year, as it was winter when RNJR set off. Then a timeskip of 6-8 months means it's been almost two years since the Red Trailer.

Ruby was 15 when she started at Beacon. If we work on Ruby starting at Beacon in the spring after the Red Trailer, so between 1 and 5 months after that, then she would be 16 now, as at most that puts the gap between the beginning of V1 and V4 at about 15 months.