I found this example:
你拿着用吧,什么时候还都可以。
Nǐ ná zheyòng ba, shénme shíhòu huán dōu kěyǐ.
You can have it as long as you want.
I am confused about the grammar structure behind 什么时候还都可以 (literally: any time you return it is ok). How is it possible 都 occurs after the verb 还 (to return)? Until now, I always saw 都 before any verb.
(什么时候还) 都可以
, just like(今天还 或者 明天还) 都可以
, take the first part as one subject.