Basically, you could try to use:
as.Date(44025)
However, you will notice error saying Error in as.Date.numeric(44025) : 'origin' must be supplied
. And that means that all you need is to know origin, i.e. starting date from which to start counting. When you check, mentioned by Bappa Das, help page for convertToDate
function, you will see that it is just a wrapper for as.Date()
function and that the default argument for origin
parameter is "1900-01-01"
.
Next, you can check, why is this, by looking for date systems in Excel and here is a page for this:
Date systems in Excel
Where is an information that for Windows (for Mac there are some exceptions) starting date is indeed "1900-01-01"
.
And now, finally, if you want to use base R, you can do:
as.Date(44025, origin = "1900-01-01")
This is vectorized function, so you can pass whole column as well.