[Gretl-users] using the time

hi I have a time series, X. the range is, let say, 1990 - 2000. The frequency is quarters. I would like to create a new series that depends on the date of X and the date of X. something like Y=X+(year of X). how can I refer to the year / quarter in which the sample was taken? thanks in advance, Raz. "I often see problems in the world and wonder why someone doesn't fix them. Then I realize that I am someone, and that makes me feel bad because it is all my fault." http://dilbert.com/blog/entry/fixing_the_world/