time2ym: Time related conversion functions
In vetools: Tools for Venezuelan Environmental Data

These functions convert between class "Date" and c(year, month) dates.

1 2	time2ym(d) ym2time(e)

`d`	object of class `"Date"` that can be converted to `c(year, month)`
`e`	object of class `"ts"`

time2ym: returns a vector of length 2 specifying year and month corresponding to a date given, compatible with commands start and end for objects of class "ts"
ym2time: returns a class "Date" object determined by the specified year and month

A.M. Sajo-Castelli