Converting factor YYYY/MM to date class in R : I have dataframe with a column of dates of the form YYYY/MM, factor class, and I wish to convert it to date class. E.g. 2000/01 -> Jan 2000

I note that as.Date() is unable to handle date formats without the day component. I have tried using the as.yearmon() function from the zoo package.

> library(zoo)   
> as.yearmon(factor("2000-01"))   
[1] "Jan 2000"      # It works with YYYY-MM format    
> as.yearmon(factor("2000/01"))  
[1] NA  
> as.yearmon(factor("2000/01"),"%y/%m")   
[1] NA  


I'm looking for a function that will turn factor("2000/01") to "Jan 2000". Any help would be kindly appreciated.