short-timer

noun4

1. •
   (US, slang) A soldier during the Vietnam War who had less than two months to serve.

   • Almost every Marine in Viet Nam carries a short-timer’s calendar of his tour of duty—the usual 365 days—plus a bonus of 20 days for being a Marine. — 1979
2. •
   (informal) An employee who has given notice of their intent to leave.
3. •
   A person who would not be required to do a difficult or dangerous task.
4. •
   (informal) The customer of a prostitute.