Don't know how to automatically pick scale for object of type yearqtr

      Date     v1     v2
1   2005 Q4   5.0   6.52274 
2   2006 Q1   4.7   6.51802 
3   2006 Q2   4.6   6.36422


Code:-

 ggplot() + geom_line(data=df, aes(x=Date, y=v1,group=1,color="v1"))

I get an error because the date is in the "yearqtr" type. Please advice. I cannot convert the date in to year because i have quarterly data. Thanks.