用偶写的小程序吧：
http://www.pinggu.org/bbs/thread-687072-1-1.html

In base package, you could do as following:
        wk <- seq(as.Date("2000/1/1"), as.Date("2010/1/1"), "weeks")
Then you can get the weekly date stamp.

There are some packages to do with time series data, such as xts, timeSeries, etc.
In the timeSeries packages,
      timeSeries(rnorm(length(wk), wk))