Format Date (Year-Month) in R [duplicate]

Answer 1

The zoo package has a "yearmon" class that directly handles year/month objects:

library(zoo)
nums <- c(1402, 1401, 1312)
ym <- as.yearmon(as.character(nums), "%y%m")

giving:

> ym
[1] "Feb 2014" "Jan 2014" "Dec 2013"