Can you provide a source or examples? Asking out of ignorance—I've worked in insurance and currently work for a US-based financial services company, but haven't heard of this practice before.

It happens at most major investment banks, although to my knowledge the mandatory "two weeker" is generally limited to employees who manage risk like traders. It forces another person on the trading desk to be responsible for their carried positions which should help identify any mismarking or other types of fraud.

https://www.wsj.com/articles/SB10000872396390444914904577615...

It is typically referred to as YAR (yearly absence requirement)

https://www.newyorkfed.org/banking/circulars/10923.html