[R] convert 12 time stamp to 24 hour

[e-letter]

Readers,

Have since tried to plot converted 24 hour data:

testtimedataset
        V1
1 13:01:41
2 13:02:10
3 13:02:38
4 13:03:05
5 13:03259

> testdata<-seq(1:5)
> plot(testdata~testtimedataset)
Error in function (formula, data = NULL, subset = NULL, na.action = na.fail,  :
  invalid type (list) for variable 'testtimedataset'

Was expecting to see a graph with ordinate values 1:5 for the time
series values on the abscissa. What is the mistake please?

--
r2151