How to remove all letters and leading numbers before year values

[Chul-Kyoo Jung]

I imported .xlsx file to stata, realizing that year values (int) looks like

01dec1981

.
Then I destring the variable using

destring year, gen(yr)

before deleting the part before 1981. But destring value turns out 8005, which is weird to me.
Is there any way to remove all the leading terms before 1981 so that my year value may look like just 1981?

Thanks.

[Klaus Klausen]

gen yr = year(year)

you may also want to have a look in the help file in the date time function chapters.

help dates and times

[Chul-Kyoo Jung]

Klaus Klausen thanks so much!